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Revision 346 - (hide annotations) (download)
Wed Apr 30 16:35:49 2008 UTC (6 years, 11 months ago) by ph10
File size: 156098 byte(s)
Fix typo in ucpinternal.h.

1 nigel 3 ChangeLog for PCRE
2     ------------------
4 ph10 345 Version 7.7 28-Apr-08
5 ph10 321 ---------------------
7     1. Applied Craig's patch to sort out a long long problem: "If we can't convert
8 ph10 345 a string to a long long, pretend we don't even have a long long." This is
9 ph10 321 done by checking for the strtoq, strtoll, and _strtoi64 functions.
10 ph10 345
11 ph10 322 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
12     pre-7.6 versions, which defined a global no_arg variable instead of putting
13 ph10 332 it in the RE class. (See also #8 below.)
14 ph10 345
15     3. Remove a line of dead code, identified by coverity and reported by Nuno
16     Lopes.
18 ph10 324 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 ph10 345 of files, instead of just to the final components.
23 ph10 324 (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 345
30 ph10 325 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
31 ph10 345 --exclude_dir in the tests to avoid scanning .svn directories.
33 ph10 326 6. Applied Craig's patch to the QuoteMeta function so that it escapes the
34 ph10 345 NUL character as backslash + 0 rather than backslash + NUL, because PCRE
35 ph10 326 doesn't support NULs in patterns.
36 ph10 345
37     7. Added some missing "const"s to declarations of static tables in
38     pcre_compile.c and pcre_dfa_exec.c.
40 ph10 328 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
41 ph10 329 caused by fix #2 above. (Subsequently also a second patch to fix the
42 ph10 345 first patch. And a third patch - this was a messy problem.)
43 ph10 321
44 ph10 345 9. Applied Craig's patch to remove the use of push_back().
46 ph10 332 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
47     matching function regexec().
48 ph10 345
49     11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
50     which, however, unlike Perl's \g{...}, are subroutine calls, not back
51 ph10 333 references. PCRE supports relative numbers with this syntax (I don't think
52     Oniguruma does).
53 ph10 345
54     12. Previously, a group with a zero repeat such as (...){0} was completely
55 ph10 335 omitted from the compiled regex. However, this means that if the group
56     was called as a subroutine from elsewhere in the pattern, things went wrong
57 ph10 345 (an internal error was given). Such groups are now left in the compiled
58     pattern, with a new opcode that causes them to be skipped at execution
59 ph10 335 time.
60 ph10 345
61 ph10 341 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
62     to the way PCRE behaves:
63 ph10 345
64 ph10 336 (a) A lone ] character is dis-allowed (Perl treats it as data).
65 ph10 345
66     (b) A back reference to an unmatched subpattern matches an empty string
67 ph10 336 (Perl fails the current match path).
68 ph10 345
69 ph10 341 (c) A data ] in a character class must be notated as \] because if the
70 ph10 345 first data character in a class is ], it defines an empty class. (In
71 ph10 341 Perl it is not possible to have an empty class.) The empty class []
72     never matches; it forces failure and is equivalent to (*FAIL) or (?!).
73     The negative empty class [^] matches any one character, independently
74     of the DOTALL setting.
75 ph10 345
76     14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
77 ph10 340 non-existent subpattern following a character class starting with ']' and
78     containing () gave an internal compiling error instead of "reference to
79     non-existent subpattern". Fortunately, when the pattern did exist, the
80 ph10 345 compiled code was correct. (When scanning forwards to check for the
81 ph10 340 existencd of the subpattern, it was treating the data ']' as terminating
82 ph10 345 the class, so got the count wrong. When actually compiling, the reference
83 ph10 340 was subsequently set up correctly.)
84 ph10 345
85 ph10 341 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
86 ph10 345 it was being rejected as not supported by pcre_dfa_exec(), even though
87     other assertions are supported. I have made pcre_dfa_exec() support
88     (*FAIL).
90 ph10 342 16. The implementation of 13c above involved the invention of a new opcode,
91 ph10 345 OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
92     cannot be changed at match time, I realized I could make a small
93     improvement to matching performance by compiling OP_ALLANY instead of
94     OP_ANY for "." when DOTALL was set, and then removing the runtime tests
95     on the OP_ANY path.
97     17. Compiling pcretest on Windows with readline support failed without the
98 ph10 343 following two fixes: (1) Make the unistd.h include conditional on
99 ph10 345 HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
101 ph10 344 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
102 ph10 345 ncurses library to be included for pcretest when ReadLine support is
103     requested, but also to allow for it to be overridden. This patch came from
104     Daniel Bergström.
105 ph10 346
106     19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
107     as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
108     any errors with the current Unicode tables. Thanks to Peter Kankowski for
109     spotting this.
110 ph10 324
111 ph10 332
112 ph10 319 Version 7.6 28-Jan-08
113 ph10 300 ---------------------
115 ph10 302 1. A character class containing a very large number of characters with
116     codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
117     overflow.
118 ph10 309
119     2. Patch to cut out the "long long" test in pcrecpp_unittest when
120     HAVE_LONG_LONG is not defined.
122 ph10 303 3. Applied Christian Ehrlicher's patch to update the CMake build files to
123 ph10 304 bring them up to date and include new features. This patch includes:
124 ph10 309
125 ph10 304 - Fixed PH's badly added libz and libbz2 support.
126     - Fixed a problem with static linking.
127 ph10 312 - Added pcredemo. [But later removed - see 7 below.]
128 ph10 304 - Fixed dftables problem and added an option.
129     - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
131     - Added readline support for pcretest.
132 ph10 309 - Added an listing of the option settings after cmake has run.
134 ph10 314 4. A user submitted a patch to Makefile that makes it easy to create
135     "pcre.dll" under mingw when using Configure/Make. I added stuff to
136     Makefile.am that cause it to include this special target, without
137     affecting anything else. Note that the same mingw target plus all
138     the other distribution libraries and programs are now supported
139     when configuring with CMake (see 6 below) instead of with
140     Configure/Make.
141 ph10 309
142 ph10 308 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
143     This is an attempt to solve the reported problem "pcrecpp::no_arg is not
144 ph10 309 exported in the Windows port". It has not yet been confirmed that the patch
145     solves the problem, but it does no harm.
146 ph10 313
147 ph10 311 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
148 ph10 319 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
149 ph10 314 with CMake, and also correct the comment about stack recursion.
150 ph10 313
151 ph10 312 7. Remove the automatic building of pcredemo from the ./configure system and
152 ph10 313 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
153     of a program that users should build themselves after PCRE is installed, so
154     building it automatically is not really right. What is more, it gave
155 ph10 312 trouble in some build environments.
156 ph10 300
157 ph10 319 8. Further tidies to CMakeLists.txt from Sheri and Christian.
158 ph10 308
159 ph10 319
160 ph10 298 Version 7.5 10-Jan-08
161 ph10 263 ---------------------
163     1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
164     values in parens when parsing an RE using the C++ wrapper."
165 ph10 286
166 ph10 264 2. Negative specials like \S did not work in character classes in UTF-8 mode.
167     Characters greater than 255 were excluded from the class instead of being
168     included.
169 ph10 286
170     3. The same bug as (2) above applied to negated POSIX classes such as
171 ph10 265 [:^space:].
172 ph10 286
173 ph10 267 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
174     defined or documented. It seems to have been a typo for PCRE_STATIC, so
175 ph10 286 I have changed it.
177 ph10 268 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
178 ph10 286 first named subpattern) and a construct such as (?&a) would reference the
179     first named subpattern whose name started with "a" (in other words, the
180 ph10 272 length check was missing). Both these problems are fixed. "Subpattern name
181     expected" is now given for (?&) (a zero-length name), and this patch also
182     makes it give the same error for \k'' (previously it complained that that
183     was a reference to a non-existent subpattern).
184 ph10 286
185 ph10 269 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
186 ph10 286 this is right because (?- can be followed by option settings as well as by
187 ph10 269 digits. I have, however, made the messages clearer.
188 ph10 286
189 ph10 270 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
190     than the number used in the conditional) now cause a compile-time error.
191     This is actually not compatible with Perl, which accepts such patterns, but
192     treats the conditional as always being FALSE (as PCRE used to), but it
193     seems to me that giving a diagnostic is better.
194 ph10 286
195 ph10 274 8. Change "alphameric" to the more common word "alphanumeric" in comments
196 ph10 275 and messages.
197 ph10 286
198     9. Fix two occurrences of "backslash" in comments that should have been
199     "backspace".
201     10. Remove two redundant lines of code that can never be obeyed (their function
202     was moved elsewhere).
204     11. The program that makes PCRE's Unicode character property table had a bug
205     which caused it to generate incorrect table entries for sequences of
206 ph10 277 characters that have the same character type, but are in different scripts.
207 ph10 286 It amalgamated them into a single range, with the script of the first of
208 ph10 277 them. In other words, some characters were in the wrong script. There were
209     thirteen such cases, affecting characters in the following ranges:
210 ph10 286
211 ph10 277 U+002b0 - U+002c1
212     U+0060c - U+0060d
213 ph10 286 U+0061e - U+00612
214 ph10 277 U+0064b - U+0065e
215     U+0074d - U+0076d
216     U+01800 - U+01805
217     U+01d00 - U+01d77
218     U+01d9b - U+01dbf
219     U+0200b - U+0200f
220     U+030fc - U+030fe
221     U+03260 - U+0327f
222     U+0fb46 - U+0fbb1
223     U+10450 - U+1049d
224 ph10 286
225 ph10 279 12. The -o option (show only the matching part of a line) for pcregrep was not
226     compatible with GNU grep in that, if there was more than one match in a
227     line, it showed only the first of them. It now behaves in the same way as
228     GNU grep.
229 ph10 286
230     13. If the -o and -v options were combined for pcregrep, it printed a blank
231     line for every non-matching line. GNU grep prints nothing, and pcregrep now
232     does the same. The return code can be used to tell if there were any
233     non-matching lines.
235 ph10 289 14. Added --file-offsets and --line-offsets to pcregrep.
237     15. The pattern (?=something)(?R) was not being diagnosed as a potentially
238 ph10 282 infinitely looping recursion. The bug was that positive lookaheads were not
239 ph10 286 being skipped when checking for a possible empty match (negative lookaheads
240     and both kinds of lookbehind were skipped).
242 ph10 289 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
243 ph10 284 inclusion of <windows.h> to before rather than after the definition of
244     INVALID_FILE_ATTRIBUTES (patch from David Byron).
245 ph10 263
246 ph10 289 17. Specifying a possessive quantifier with a specific limit for a Unicode
247 ph10 286 character property caused pcre_compile() to compile bad code, which led at
248     runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
249     are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
250     caused the error; without that there was no problem.
251 ph10 263
252 ph10 289 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
253 ph10 286
254 ph10 289 19. Added --enable-pcretest-libreadline.
255 ph10 286
256 ph10 289 20. In pcrecpp.cc, the variable 'count' was incremented twice in
257 ph10 288 RE::GlobalReplace(). As a result, the number of replacements returned was
258 ph10 298 double what it should be. I removed one of the increments, but Craig sent a
259     later patch that removed the other one (the right fix) and added unit tests
260     that check the return values (which was not done before).
261 ph10 292
262 ph10 291 21. Several CMake things:
263 ph10 287
264 ph10 291 (1) Arranged that, when cmake is used on Unix, the libraries end up with
265 ph10 292 the names libpcre and libpcreposix, not just pcre and pcreposix.
266 ph10 288
267 ph10 292 (2) The above change means that pcretest and pcregrep are now correctly
268     linked with the newly-built libraries, not previously installed ones.
269 ph10 291
271 ph10 298
272     22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
273     crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
274     UTF-8 newline character). The key issue is that the pattern starts .*;
275     this means that the match must be either at the beginning, or after a
276     newline. The bug was in the code for advancing after a failed match and
277     checking that the new position followed a newline. It was not taking
278 ph10 294 account of UTF-8 characters correctly.
279 ph10 298
280     23. PCRE was behaving differently from Perl in the way it recognized POSIX
281     character classes. PCRE was not treating the sequence [:...:] as a
282     character class unless the ... were all letters. Perl, however, seems to
283     allow any characters between [: and :], though of course it rejects as
284     unknown any "names" that contain non-letters, because all the known class
285     names consist only of letters. Thus, Perl gives an error for [[:1234:]],
286     for example, whereas PCRE did not - it did not recognize a POSIX character
287     class. This seemed a bit dangerous, so the code has been changed to be
288     closer to Perl. The behaviour is not identical to Perl, because PCRE will
289     diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
290     treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
291     Perl does, and where it didn't before.
293 ph10 296 24. Rewrite so as to remove the single use of %n from pcregrep because in some
294     Windows environments %n is disabled by default.
295 ph10 292
297 ph10 260 Version 7.4 21-Sep-07
298 ph10 230 ---------------------
300     1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
301 ph10 231 means that a class such as [\s] counted as "explicit reference to CR or
302     LF". That isn't really right - the whole point of the change was to try to
303     help when there was an actual mention of one of the two characters. So now
304     the change happens only if \r or \n (or a literal CR or LF) character is
305 ph10 230 encountered.
306 ph10 231
307     2. The 32-bit options word was also used for 6 internal flags, but the numbers
308     of both had grown to the point where there were only 3 bits left.
309     Fortunately, there was spare space in the data structure, and so I have
310     moved the internal flags into a new 16-bit field to free up more option
311 ph10 230 bits.
312 ph10 231
313     3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
314     but did not set the internal JCHANGED flag - either of these is enough to
315     control the way the "get" function works - but the PCRE_INFO_JCHANGED
316     facility is supposed to tell if (?J) was ever used, so now (?J) at the
317 ph10 230 start sets both bits.
319 ph10 231 4. Added options (at build time, compile time, exec time) to change \R from
320     matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
321 ph10 230
322 ph10 243 5. doc/pcresyntax.html was missing from the distribution.
324     6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
325 ph10 233 compatibility, even though it is no longer used.
326 ph10 243
327     7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
328 ph10 254 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
329 ph10 259 windows.h file is present (where different names are used). [This was
330 ph10 257 reversed later after testing - see 16 below.]
331 ph10 243
332     8. Changed all #include <config.h> to #include "config.h". There were also
333 ph10 236 some further <pcre.h> cases that I changed to "pcre.h".
334 ph10 243
335 ph10 239 9. When pcregrep was used with the --colour option, it missed the line ending
336 ph10 243 sequence off the lines that it output.
338     10. It was pointed out to me that arrays of string pointers cause lots of
339     relocations when a shared library is dynamically loaded. A technique of
340     using a single long string with a table of offsets can drastically reduce
341     these. I have refactored PCRE in four places to do this. The result is
342 ph10 240 dramatic:
343 ph10 243
344 ph10 240 Originally: 290
345     After changing UCP table: 187
346 ph10 243 After changing error message table: 43
347 ph10 240 After changing table of "verbs" 36
348     After changing table of Posix names 22
349 ph10 243
350 ph10 240 Thanks to the folks working on Gregex for glib for this insight.
351 ph10 247
352 ph10 244 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
353 ph10 247 unicode-properties was also set.
355 ph10 248 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
356 ph10 231
357 ph10 253 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
358     checked only for CRLF.
359 ph10 233
360 ph10 259 14. Added casts to pcretest.c to avoid compiler warnings.
362 ph10 256 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
363 ph10 253
364 ph10 257 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
365 ph10 259 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
366     entirely. This removes changes made in 7 above.
367 ph10 256
368 ph10 261 17. The CMake files have been updated, and there is now more information about
369     building with CMake in the NON-UNIX-USE document.
370 ph10 257
371 ph10 261
372 ph10 228 Version 7.3 28-Aug-07
373 ph10 157 ---------------------
375 ph10 189 1. In the rejigging of the build system that eventually resulted in 7.1, the
376     line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
377     brackets there is not right, since it causes compilers to look for an
378     installed pcre.h, not the version that is in the source that is being
379     compiled (which of course may be different). I have changed it back to:
380 ph10 197
381 ph10 189 #include "pcre.h"
382 ph10 197
383     I have a vague recollection that the change was concerned with compiling in
384     different directories, but in the new build system, that is taken care of
385     by the VPATH setting the Makefile.
387 ph10 190 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
388     when the subject happened to end in the byte 0x85 (e.g. if the last
389     character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
390     characters but of course it shouldn't be taken as a newline when it is part
391     of another character. The bug was that, for an unlimited repeat of . in
392     not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
393     characters when looking for a newline.
394 ph10 197
395     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
397     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
398     in debug output.
400 ph10 201 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
401     long printing in the pcrecpp unittest when running under MinGW.
402 ph10 189
403 ph10 197 6. ESC_K was left out of the EBCDIC table.
404 ph10 189
405 ph10 197 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
406     parentheses; I made it 1000, which seemed large enough. Unfortunately, the
407     limit also applies to "virtual nesting" when a pattern is recursive, and in
408     this case 1000 isn't so big. I have been able to remove this limit at the
409     expense of backing off one optimization in certain circumstances. Normally,
410     when pcre_exec() would call its internal match() function recursively and
411     immediately return the result unconditionally, it uses a "tail recursion"
412     feature to save stack. However, when a subpattern that can match an empty
413     string has an unlimited repetition quantifier, it no longer makes this
414     optimization. That gives it a stack frame in which to save the data for
415     checking that an empty string has been matched. Previously this was taken
416     from the 1000-entry workspace that had been reserved. So now there is no
417     explicit limit, but more stack is used.
418 ph10 189
419 ph10 200 8. Applied Daniel's patches to solve problems with the import/export magic
420     syntax that is required for Windows, and which was going wrong for the
421     pcreposix and pcrecpp parts of the library. These were overlooked when this
422     problem was solved for the main library.
423 ph10 197
424 ph10 202 9. There were some crude static tests to avoid integer overflow when computing
425     the size of patterns that contain repeated groups with explicit upper
426     limits. As the maximum quantifier is 65535, the maximum group length was
427     set at 30,000 so that the product of these two numbers did not overflow a
428     32-bit integer. However, it turns out that people want to use groups that
429     are longer than 30,000 bytes (though not repeat them that many times).
430     Change 7.0/17 (the refactoring of the way the pattern size is computed) has
431     made it possible to implement the integer overflow checks in a much more
432     dynamic way, which I have now done. The artificial limitation on group
433     length has been removed - we now have only the limit on the total length of
434     the compiled pattern, which depends on the LINK_SIZE setting.
435 ph10 208
436     10. Fixed a bug in the documentation for get/copy named substring when
437     duplicate names are permitted. If none of the named substrings are set, the
438     functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
439     empty string.
441     11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
442     instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
443     because the ] is interpreted as the first data character and the
444     terminating ] is not found. PCRE has been made compatible with Perl in this
445     regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
446     cause memory overwriting.
448 ph10 206 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
449     string has been matched (to stop an infinite loop). It was not recognizing
450 ph10 208 a conditional subpattern that could match an empty string if that
451 ph10 206 subpattern was within another subpattern. For example, it looped when
452 ph10 208 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
453 ph10 206 condition was not nested. This bug has been fixed.
454 ph10 208
455 ph10 207 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
456     past the start of the subject in the presence of bytes with the top bit
457     set, for example "\x8aBCD".
458 ph10 211
459 ph10 210 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
460     (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
461 ph10 200
462 ph10 211 14. Optimized (?!) to (*FAIL).
463 ph10 202
464 ph10 212 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
465     This restricts code points to be within the range 0 to 0x10FFFF, excluding
466     the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
467     full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
468     does: it's just the validity check that is more restrictive.
469 ph10 220
470     16. Inserted checks for integer overflows during escape sequence (backslash)
471     processing, and also fixed erroneous offset values for syntax errors during
472     backslash processing.
474 ph10 214 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
475 ph10 220 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
477 ph10 215 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
478     caused an overrun.
479 ph10 220
480     19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
481     something other than just ASCII characters) inside a group that had an
482     unlimited repeat caused a loop at compile time (while checking to see
483     whether the group could match an empty string).
485 ph10 217 20. Debugging a pattern containing \p or \P could cause a crash. For example,
486     [\P{Any}] did so. (Error in the code for printing property names.)
487 ph10 210
488 ph10 220 21. An orphan \E inside a character class could cause a crash.
490     22. A repeated capturing bracket such as (A)? could cause a wild memory
491 ph10 218 reference during compilation.
492 ph10 220
493     23. There are several functions in pcre_compile() that scan along a compiled
494     expression for various reasons (e.g. to see if it's fixed length for look
495 ph10 218 behind). There were bugs in these functions when a repeated \p or \P was
496 ph10 220 present in the pattern. These operators have additional parameters compared
497     with \d, etc, and these were not being taken into account when moving along
498 ph10 218 the compiled data. Specifically:
499 ph10 220
500     (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
501     length.
503     (b) An item such as \pL+ within a repeated group could cause crashes or
504 ph10 218 loops.
505 ph10 220
506 ph10 218 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
507 ph10 220 "reference to non-existent subpattern" error.
509 ph10 221 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
511 ph10 219 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
512 ph10 220 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
513 ph10 211
514 ph10 222 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
515 ph10 218
516 ph10 227 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
517 ph10 223 character were causing crashes (broken optimization).
518 ph10 227
519 ph10 224 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
520 ph10 227 \p or \P) caused a compile-time loop.
522 ph10 226 28. More problems have arisen in unanchored patterns when CRLF is a valid line
523     break. For example, the unstudied pattern [\r\n]A does not match the string
524     "\r\nA" because change 7.0/46 below moves the current point on by two
525     characters after failing to match at the start. However, the pattern \nA
526 ph10 227 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
527     the same is true. There doesn't seem any very clean way out of this, but
528     what I have chosen to do makes the common cases work: PCRE now takes note
529     of whether there can be an explicit match for \r or \n anywhere in the
530     pattern, and if so, 7.0/46 no longer applies. As part of this change,
531     there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
532     pattern has explicit CR or LF references.
533 ph10 222
534 ph10 227 29. Added (*CR) etc for changing newline setting at start of pattern.
535 ph10 223
536 ph10 227
537 ph10 189 Version 7.2 19-Jun-07
538     ---------------------
540 ph10 157 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
541     which is apparently normally available under Windows.
542 ph10 159
543     2. Re-jig the pcregrep tests with different newline settings in an attempt
544     to make them independent of the local environment's newline setting.
545 ph10 157
546 ph10 160 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
547 ph10 165
548 ph10 161 4. Some of the "internals" tests were previously cut out when the link size
549     was not 2, because the output contained actual offsets. The recent new
550 ph10 165 "Z" feature of pcretest means that these can be cut out, making the tests
551     usable with all link sizes.
553 ph10 164 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
554     stack recursion. This gives a massive performance boost under BSD, but just
555 ph10 165 a small improvement under Linux. However, it saves one field in the frame
556 ph10 164 in all cases.
557 ph10 172
558 ph10 166 6. Added more features from the forthcoming Perl 5.10:
559 ph10 172
560 ph10 166 (a) (?-n) (where n is a string of digits) is a relative subroutine or
561     recursion call. It refers to the nth most recently opened parentheses.
562 ph10 172
563 ph10 166 (b) (?+n) is also a relative subroutine call; it refers to the nth next
564 ph10 172 to be opened parentheses.
566     (c) Conditions that refer to capturing parentheses can be specified
567 ph10 167 relatively, for example, (?(-2)... or (?(+3)...
568 ph10 172
569 ph10 168 (d) \K resets the start of the current match so that everything before
570 ph10 172 is not part of it.
572 ph10 171 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
573 ph10 172
574 ph10 171 (f) \g{name} is another synonym - part of Perl 5.10's unification of
575 ph10 172 reference syntax.
576 ph10 182
577 ph10 175 (g) (?| introduces a group in which the numbering of parentheses in each
578 ph10 182 alternative starts with the same number.
579 ph10 172
580 ph10 182 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
582 ph10 172 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
585     8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
586     terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
587 ph10 170 for detecting groups that can match an empty string.
588 ph10 159
589 ph10 172 9. A pattern with a very large number of alternatives (more than several
590     hundred) was running out of internal workspace during the pre-compile
591     phase, where pcre_compile() figures out how much memory will be needed. A
592     bit of new cunning has reduced the workspace needed for groups with
593     alternatives. The 1000-alternative test pattern now uses 12 bytes of
594     workspace instead of running out of the 4096 that are available.
595 ph10 182
596 ph10 176 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
597 ph10 172
598 ph10 179 11. Applied patch from Google to remove an optimization that didn't quite work.
599     The report of the bug said:
600 ph10 182
601 ph10 179 pcrecpp::RE("a*").FullMatch("aaa") matches, while
602     pcrecpp::RE("a*?").FullMatch("aaa") does not, and
603 ph10 182 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
604 ph10 185
605 ph10 184 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
606 ph10 185 it matched the wrong number of bytes.
607 ph10 172
608 ph10 179
609 ph10 155 Version 7.1 24-Apr-07
610 ph10 98 ---------------------
612 ph10 111 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
613 ph10 122 that is more "standard", making use of automake and other Autotools. There
614 ph10 99 is some re-arrangement of the files and adjustment of comments consequent
615     on this.
616 ph10 111
617     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
618     for recursive directory scanning broke on some systems because the files
619     are not scanned in any specific order and on different systems the order
620     was different. A call to "sort" has been inserted into RunGrepTest for the
621     approprate test as a short-term fix. In the longer term there may be an
622 ph10 100 alternative.
623 ph10 111
624 ph10 100 3. I had an email from Eric Raymond about problems translating some of PCRE's
625 ph10 111 man pages to HTML (despite the fact that I distribute HTML pages, some
626     people do their own conversions for various reasons). The problems
627     concerned the use of low-level troff macros .br and .in. I have therefore
628     removed all such uses from the man pages (some were redundant, some could
629 ph10 113 be replaced by .nf/.fi pairs). The 132html script that I use to generate
630     HTML has been updated to handle .nf/.fi and to complain if it encounters
631     .br or .in.
632 ph10 111
633 ph10 100 4. Updated comments in configure.ac that get placed in config.h.in and also
634 ph10 123 arranged for config.h to be included in the distribution, with the name
635 ph10 111 config.h.generic, for the benefit of those who have to compile without
636     Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
638     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
639     Weber: (1) pcre_internal.h was missing some function renames; (2) updated
640 ph10 127 makevp.bat for the current PCRE, using the additional files
641 ph10 135 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
642 ph10 111
643     6. A Windows user reported a minor discrepancy with test 2, which turned out
644     to be caused by a trailing space on an input line that had got lost in his
645 ph10 102 copy. The trailing space was an accident, so I've just removed it.
646 ph10 111
647 ph10 104 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
648 ph10 111 that is needed.
650 ph10 105 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
651     as "const" (a) because they are and (b) because it helps the PHP
652     maintainers who have recently made a script to detect big data structures
653 ph10 111 in the php code that should be moved to the .rodata section. I remembered
654     to update Builducptable as well, so it won't revert if ucptable.h is ever
655 ph10 105 re-created.
656 ph10 111
657     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
658 ph10 107 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
659 ph10 111 order to be able to cut out the UTF-8 tables in the latter when UTF-8
660     support is not required. This saves 1.5-2K of code, which is important in
661 ph10 107 some applications.
662 ph10 111
663 ph10 110 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
664 ph10 111 so as not to refer to the tables, even though these functions will never be
665     called when UTF-8 support is disabled. Otherwise there are problems with a
666     shared library.
668 ph10 118 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
670     (a) It was defining its arguments as char * instead of void *.
672 ph10 123 (b) It was assuming that all moves were upwards in memory; this was true
673     a long time ago when I wrote it, but is no longer the case.
675 ph10 118 The emulated memove() is provided for those environments that have neither
676 ph10 123 memmove() nor bcopy(). I didn't think anyone used it these days, but that
677 ph10 118 is clearly not the case, as these two bugs were recently reported.
678 ph10 123
679 ph10 111 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
680 ph10 123 and Detrail to create the HTML documentation, the .txt form of the man
681     pages, and it removes trailing spaces from listed files. It also creates
682     pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
683     case, it wraps all the #defines with #ifndefs. This script should be run
684 ph10 111 before "make dist".
685 ph10 123
686 ph10 115 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
687     with Unicode property support.
688 ph10 123
689     (a) For a maximizing quantifier, if the two different cases of the
690     character were of different lengths in their UTF-8 codings (there are
691     some cases like this - I found 11), and the matching function had to
692 ph10 115 back up over a mixture of the two cases, it incorrectly assumed they
693     were both the same length.
694 ph10 123
695     (b) When PCRE was configured to use the heap rather than the stack for
696     recursion during matching, it was not correctly preserving the data for
697     the other case of a UTF-8 character when checking ahead for a match
698     while processing a minimizing repeat. If the check also involved
699 ph10 115 matching a wide character, but failed, corruption could cause an
700     erroneous result when trying to check for a repeat of the original
701     character.
702 ph10 123
703 ph10 116 13. Some tidying changes to the testing mechanism:
704 ph10 98
705 ph10 116 (a) The RunTest script now detects the internal link size and whether there
706     is UTF-8 and UCP support by running ./pcretest -C instead of relying on
707 ph10 123 values substituted by "configure". (The RunGrepTest script already did
708     this for UTF-8.) The configure.ac script no longer substitutes the
709     relevant variables.
711 ph10 116 (b) The debugging options /B and /D in pcretest show the compiled bytecode
712     with length and offset values. This means that the output is different
713     for different internal link sizes. Test 2 is skipped for link sizes
714     other than 2 because of this, bypassing the problem. Unfortunately,
715     there was also a test in test 3 (the locale tests) that used /B and
716 ph10 123 failed for link sizes other than 2. Rather than cut the whole test out,
717     I have added a new /Z option to pcretest that replaces the length and
718     offset values with spaces. This is now used to make test 3 independent
719 ph10 122 of link size. (Test 2 will be tidied up later.)
720 ph10 123
721     14. If erroroffset was passed as NULL to pcre_compile, it provoked a
722 ph10 122 segmentation fault instead of returning the appropriate error message.
723 ph10 134
724 ph10 131 15. In multiline mode when the newline sequence was set to "any", the pattern
725 ph10 134 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
726     This doesn't seem right; it now treats the CRLF combination as the line
727     ending, and so does not match in that case. It's only a pattern such as ^$
728     that would hit this one: something like ^ABC$ would have failed after \r
729     and then tried again after \r\n.
731 ph10 131 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
732 ph10 134 in an attempt to make files that differ only in their line terminators
733     compare equal. This works on Linux.
734 ph10 142
735 ph10 141 17. Under certain error circumstances pcregrep might try to free random memory
736     as it exited. This is now fixed, thanks to valgrind.
737 ph10 142
738 ph10 141 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
739 ph10 142 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
740     was because its rules for how to advance for /g after matching an empty
741 ph10 143 string at the end of a line did not allow for this case. They now check for
742     it specially.
743 ph10 150
744     20. pcretest is supposed to handle patterns and data of any length, by
745     extending its buffers when necessary. It was getting this wrong when the
746 ph10 147 buffer for a data line had to be extended.
747 ph10 150
748 ph10 149 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
749 ph10 150 CRLF as a newline sequence.
750 ph10 152
751 ph10 151 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
752 ph10 152 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
753     I have nevertheless tidied it up.
754 ph10 111
755 ph10 152 23. Added some casts to kill warnings from HP-UX ia64 compiler.
756 ph10 123
757 ph10 153 24. Added a man page for pcre-config.
758 ph10 152
759 ph10 153
760 nigel 93 Version 7.0 19-Dec-06
761     ---------------------
763     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
764     moving to gcc 4.1.1.
766     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
767     sys/time.h, which is documented as needed for this function. It doesn't
768     seem to matter on Linux, but it showed up on some releases of OS X.
770     3. It seems that there are systems where bytes whose values are greater than
771     127 match isprint() in the "C" locale. The "C" locale should be the
772     default when a C program starts up. In most systems, only ASCII printing
773     characters match isprint(). This difference caused the output from pcretest
774     to vary, making some of the tests fail. I have changed pcretest so that:
776     (a) When it is outputting text in the compiled version of a pattern, bytes
777     other than 32-126 are always shown as hex escapes.
779     (b) When it is outputting text that is a matched part of a subject string,
780     it does the same, unless a different locale has been set for the match
781     (using the /L modifier). In this case, it uses isprint() to decide.
783     4. Fixed a major bug that caused incorrect computation of the amount of memory
784     required for a compiled pattern when options that changed within the
785     pattern affected the logic of the preliminary scan that determines the
786     length. The relevant options are -x, and -i in UTF-8 mode. The result was
787     that the computed length was too small. The symptoms of this bug were
788     either the PCRE error "internal error: code overflow" from pcre_compile(),
789     or a glibc crash with a message such as "pcretest: free(): invalid next
790     size (fast)". Examples of patterns that provoked this bug (shown in
791     pcretest format) are:
793     /(?-x: )/x
794     /(?x)(?-x: \s*#\s*)/
795     /((?i)[\x{c0}])/8
796     /(?i:[\x{c0}])/8
798     HOWEVER: Change 17 below makes this fix obsolete as the memory computation
799     is now done differently.
801     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
802     wrapper classes; (b) implement a new function in the C++ scanner that is
803     more efficient than the old way of doing things because it avoids levels of
804     recursion in the regex matching; (c) add a paragraph to the documentation
805     for the FullMatch() function.
807     6. The escape sequence \n was being treated as whatever was defined as
808     "newline". Not only was this contrary to the documentation, which states
809     that \n is character 10 (hex 0A), but it also went horribly wrong when
810     "newline" was defined as CRLF. This has been fixed.
812     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
813     was being set to -1 for the "end of line" case (supposedly a value that no
814     character can have). Though this value is never used (the check for end of
815     line is "zero bytes in current character"), it caused compiler complaints.
816     I've changed it to 0xffffffff.
818     8. In pcre_version.c, the version string was being built by a sequence of
819     C macros that, in the event of PCRE_PRERELEASE being defined as an empty
820     string (as it is for production releases) called a macro with an empty
821     argument. The C standard says the result of this is undefined. The gcc
822     compiler treats it as an empty string (which was what was wanted) but it is
823     reported that Visual C gives an error. The source has been hacked around to
824     avoid this problem.
826     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
827     builds of pcretest, and changed the call to _setmode() to use _O_BINARY
828     instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
829     of them did).
831     10. Originally, pcretest opened its input and output without "b"; then I was
832     told that "b" was needed in some environments, so it was added for release
833     5.0 to both the input and output. (It makes no difference on Unix-like
834     systems.) Later I was told that it is wrong for the input on Windows. I've
835     now abstracted the modes into two macros, to make it easier to fiddle with
836     them, and removed "b" from the input mode under Windows.
838     11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
840     12. Added -help and --help to pcretest as an official way of being reminded
841     of the options.
843     13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
844     and pcrecpp.cc because they annoy compilers at high warning levels.
846     14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
848     15. Fixed an occurrence of == in configure.ac that should have been = (shell
849     scripts are not C programs :-) and which was not noticed because it works
850     on Linux.
852     16. pcretest is supposed to handle any length of pattern and data line (as one
853     line or as a continued sequence of lines) by extending its input buffer if
854     necessary. This feature was broken for very long pattern lines, leading to
855     a string of junk being passed to pcre_compile() if the pattern was longer
856     than about 50K.
858     17. I have done a major re-factoring of the way pcre_compile() computes the
859     amount of memory needed for a compiled pattern. Previously, there was code
860     that made a preliminary scan of the pattern in order to do this. That was
861     OK when PCRE was new, but as the facilities have expanded, it has become
862     harder and harder to keep it in step with the real compile phase, and there
863     have been a number of bugs (see for example, 4 above). I have now found a
864     cunning way of running the real compile function in a "fake" mode that
865     enables it to compute how much memory it would need, while actually only
866     ever using a few hundred bytes of working memory and without too many
867     tests of the mode. This should make future maintenance and development
868     easier. A side effect of this work is that the limit of 200 on the nesting
869     depth of parentheses has been removed (though this was never a serious
870     limitation, I suspect). However, there is a downside: pcre_compile() now
871     runs more slowly than before (30% or more, depending on the pattern). I
872     hope this isn't a big issue. There is no effect on runtime performance.
874     18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
875     newline (only possible for the last line of a file) and it was a
876     pattern that set a locale (followed by /Lsomething), pcretest crashed.
878     19. Added additional timing features to pcretest. (1) The -tm option now times
879     matching only, not compiling. (2) Both -t and -tm can be followed, as a
880     separate command line item, by a number that specifies the number of
881     repeats to use when timing. The default is 50000; this gives better
882     precision, but takes uncomfortably long for very large patterns.
884     20. Extended pcre_study() to be more clever in cases where a branch of a
885     subpattern has no definite first character. For example, (a*|b*)[cd] would
886     previously give no result from pcre_study(). Now it recognizes that the
887     first character must be a, b, c, or d.
889     21. There was an incorrect error "recursive call could loop indefinitely" if
890     a subpattern (or the entire pattern) that was being tested for matching an
891     empty string contained only one non-empty item after a nested subpattern.
892     For example, the pattern (?>\x{100}*)\d(?R) provoked this error
893     incorrectly, because the \d was being skipped in the check.
895     22. The pcretest program now has a new pattern option /B and a command line
896     option -b, which is equivalent to adding /B to every pattern. This causes
897     it to show the compiled bytecode, without the additional information that
898     -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
899     is the same as /B/I).
901     23. A new optimization is now able automatically to treat some sequences such
902     as a*b as a*+b. More specifically, if something simple (such as a character
903     or a simple class like \d) has an unlimited quantifier, and is followed by
904     something that cannot possibly match the quantified thing, the quantifier
905     is automatically "possessified".
907     24. A recursive reference to a subpattern whose number was greater than 39
908     went wrong under certain circumstances in UTF-8 mode. This bug could also
909     have affected the operation of pcre_study().
911     25. Realized that a little bit of performance could be had by replacing
912     (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
914     26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
916     27. Possessive quantifiers such as a++ were previously implemented by turning
917     them into atomic groups such as ($>a+). Now they have their own opcodes,
918     which improves performance. This includes the automatically created ones
919     from 23 above.
921     28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
922     lookahead was broken if it was not anchored. PCRE was mistakenly expecting
923     the first matched character to be a colon. This applied both to named and
924     numbered groups.
926     29. The ucpinternal.h header file was missing its idempotency #ifdef.
928     30. I was sent a "project" file called libpcre.a.dev which I understand makes
929     building PCRE on Windows easier, so I have included it in the distribution.
931     31. There is now a check in pcretest against a ridiculously large number being
932     returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
933     loop, the loop is abandoned.
935     32. Forward references to subpatterns in conditions such as (?(2)...) where
936     subpattern 2 is defined later cause pcre_compile() to search forwards in
937     the pattern for the relevant set of parentheses. This search went wrong
938     when there were unescaped parentheses in a character class, parentheses
939     escaped with \Q...\E, or parentheses in a #-comment in /x mode.
941     33. "Subroutine" calls and backreferences were previously restricted to
942     referencing subpatterns earlier in the regex. This restriction has now
943     been removed.
945     34. Added a number of extra features that are going to be in Perl 5.10. On the
946     whole, these are just syntactic alternatives for features that PCRE had
947     previously implemented using the Python syntax or my own invention. The
948     other formats are all retained for compatibility.
950     (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
951     as (?P<name>...). The new forms, as well as being in Perl 5.10, are
952     also .NET compatible.
954     (b) A recursion or subroutine call to a named group can now be defined as
955     (?&name) as well as (?P>name).
957     (c) A backreference to a named group can now be defined as \k<name> or
958     \k'name' as well as (?P=name). The new forms, as well as being in Perl
959     5.10, are also .NET compatible.
961     (d) A conditional reference to a named group can now use the syntax
962     (?(<name>) or (?('name') as well as (?(name).
964     (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
965     groups (named and numbered) that are never evaluated inline, but can be
966     called as "subroutines" from elsewhere. In effect, the DEFINE condition
967     is always false. There may be only one alternative in such a group.
969     (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
970     as the simple (?(R). The condition is true only if the most recent
971     recursion is that of the given number or name. It does not search out
972     through the entire recursion stack.
974     (g) The escape \gN or \g{N} has been added, where N is a positive or
975     negative number, specifying an absolute or relative reference.
977     35. Tidied to get rid of some further signed/unsigned compiler warnings and
978     some "unreachable code" warnings.
980     36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
981     things, this adds five new scripts.
983     37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
984     There were also incompatibilities regarding the handling of \Q..\E inside
985     character classes, for example with patterns like [\Qa\E-\Qz\E] where the
986     hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
988     38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
989     matches an empty string, and forcibly breaks the loop. There were bugs in
990     this code in non-simple cases. For a pattern such as ^(a()*)* matched
991     against aaaa the result was just "a" rather than "aaaa", for example. Two
992     separate and independent bugs (that affected different cases) have been
993     fixed.
995     39. Refactored the code to abolish the use of different opcodes for small
996     capturing bracket numbers. This is a tidy that I avoided doing when I
997     removed the limit on the number of capturing brackets for 3.5 back in 2001.
998     The new approach is not only tidier, it makes it possible to reduce the
999     memory needed to fix the previous bug (38).
1001     40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
1002     sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
1003     processing dot, circumflex, or dollar metacharacters, or #-comments in /x
1004     mode.
1006     41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
1007     report.
1009     42. Applied patch, originally from Ari Pollak, modified by Google, to allow
1010     copy construction and assignment in the C++ wrapper.
1012     43. Updated pcregrep to support "--newline=any". In the process, I fixed a
1013     couple of bugs that could have given wrong results in the "--newline=crlf"
1014     case.
1016     44. Added a number of casts and did some reorganization of signed/unsigned int
1017     variables following suggestions from Dair Grant. Also renamed the variable
1018     "this" as "item" because it is a C++ keyword.
1020     45. Arranged for dftables to add
1022     #include "pcre_internal.h"
1024     to pcre_chartables.c because without it, gcc 4.x may remove the array
1025     definition from the final binary if PCRE is built into a static library and
1026     dead code stripping is activated.
1028     46. For an unanchored pattern, if a match attempt fails at the start of a
1029     newline sequence, and the newline setting is CRLF or ANY, and the next two
1030     characters are CRLF, advance by two characters instead of one.
1033 nigel 91 Version 6.7 04-Jul-06
1034     ---------------------
1036     1. In order to handle tests when input lines are enormously long, pcretest has
1037     been re-factored so that it automatically extends its buffers when
1038     necessary. The code is crude, but this _is_ just a test program. The
1039     default size has been increased from 32K to 50K.
1041     2. The code in pcre_study() was using the value of the re argument before
1042     testing it for NULL. (Of course, in any sensible call of the function, it
1043     won't be NULL.)
1045     3. The memmove() emulation function in pcre_internal.h, which is used on
1046     systems that lack both memmove() and bcopy() - that is, hardly ever -
1047     was missing a "static" storage class specifier.
1049     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
1050     containing an extended class (one that cannot be represented by a bitmap
1051     because it contains high-valued characters or Unicode property items, e.g.
1052     [\pZ]). Almost always one would set UTF-8 mode when processing such a
1053     pattern, but PCRE should not loop if you do not (it no longer does).
1054     [Detail: two cases were found: (a) a repeated subpattern containing an
1055     extended class; (b) a recursive reference to a subpattern that followed a
1056     previous extended class. It wasn't skipping over the extended class
1057     correctly when UTF-8 mode was not set.]
1059     5. A negated single-character class was not being recognized as fixed-length
1060     in lookbehind assertions such as (?<=[^f]), leading to an incorrect
1061     compile error "lookbehind assertion is not fixed length".
1063     6. The RunPerlTest auxiliary script was showing an unexpected difference
1064     between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
1065     write a Perl script that can interpret lines of an input file either as
1066     byte characters or as UTF-8, which is what "perltest" was being required to
1067     do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
1068     can't do is switch easily at run time between having the "use utf8;" pragma
1069     or not. In the end, I fudged it by using the RunPerlTest script to insert
1070     "use utf8;" explicitly for the UTF-8 tests.
1072     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
1073     the end of the subject string, contrary to the documentation and to what
1074     Perl does. This was true of both matching functions. Now it matches only at
1075     the start of the subject and immediately after *internal* newlines.
1077     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
1078     a pointer to an int instead of a pointer to an unsigned long int. This
1079     caused problems on 64-bit systems.
1081     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
1082     instance of the 'standard' template library not being so standard".
1084     10. There was no check on the number of named subpatterns nor the maximum
1085     length of a subpattern name. The product of these values is used to compute
1086     the size of the memory block for a compiled pattern. By supplying a very
1087     long subpattern name and a large number of named subpatterns, the size
1088     computation could be caused to overflow. This is now prevented by limiting
1089     the length of names to 32 characters, and the number of named subpatterns
1090     to 10,000.
1092     11. Subpatterns that are repeated with specific counts have to be replicated in
1093     the compiled pattern. The size of memory for this was computed from the
1094     length of the subpattern and the repeat count. The latter is limited to
1095     65535, but there was no limit on the former, meaning that integer overflow
1096     could in principle occur. The compiled length of a repeated subpattern is
1097     now limited to 30,000 bytes in order to prevent this.
1099     12. Added the optional facility to have named substrings with the same name.
1101     13. Added the ability to use a named substring as a condition, using the
1102     Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
1103     are numbers (not recommended). Forward references are permitted.
1105     14. Added forward references in named backreferences (if you see what I mean).
1107     15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
1108     pattern could run off the end of the subject. For example, the pattern
1109     "(?s)(.{1,5})"8 did this with the subject "ab".
1111     16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
1112     PCRE_CASELESS was set when matching characters that were quantified with ?
1113     or *.
1115     17. A character class other than a single negated character that had a minimum
1116     but no maximum quantifier - for example [ab]{6,} - was not handled
1117     correctly by pce_dfa_exec(). It would match only one character.
1119     18. A valid (though odd) pattern that looked like a POSIX character
1120     class but used an invalid character after [ (for example [[,abc,]]) caused
1121     pcre_compile() to give the error "Failed: internal error: code overflow" or
1122     in some cases to crash with a glibc free() error. This could even happen if
1123     the pattern terminated after [[ but there just happened to be a sequence of
1124     letters, a binary zero, and a closing ] in the memory that followed.
1126     19. Perl's treatment of octal escapes in the range \400 to \777 has changed
1127     over the years. Originally (before any Unicode support), just the bottom 8
1128     bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1129     output from "man perlunicode" includes this:
1131     The regular expression compiler produces polymorphic opcodes. That
1132     is, the pattern adapts to the data and automatically switches to
1133     the Unicode character scheme when presented with Unicode data--or
1134     instead uses a traditional byte scheme when presented with byte
1135     data.
1137     Sadly, a wide octal escape does not cause a switch, and in a string with
1138     no other multibyte characters, these octal escapes are treated as before.
1139     Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
1140     /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1141     Unicode string.
1143     I have not perpetrated such confusion in PCRE. Up till now, it took just
1144     the bottom 8 bits, as in old Perl. I have now made octal escapes with
1145     values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1146     translate to the appropriate multibyte character.
1148     29. Applied some refactoring to reduce the number of warnings from Microsoft
1149     and Borland compilers. This has included removing the fudge introduced
1150     seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1151     a warning about an unused variable.
1153     21. PCRE has not included VT (character 0x0b) in the set of whitespace
1154     characters since release 4.0, because Perl (from release 5.004) does not.
1155     [Or at least, is documented not to: some releases seem to be in conflict
1156     with the documentation.] However, when a pattern was studied with
1157     pcre_study() and all its branches started with \s, PCRE still included VT
1158     as a possible starting character. Of course, this did no harm; it just
1159     caused an unnecessary match attempt.
1161     22. Removed a now-redundant internal flag bit that recorded the fact that case
1162     dependency changed within the pattern. This was once needed for "required
1163     byte" processing, but is no longer used. This recovers a now-scarce options
1164     bit. Also moved the least significant internal flag bit to the most-
1165     significant bit of the word, which was not previously used (hangover from
1166     the days when it was an int rather than a uint) to free up another bit for
1167     the future.
1169     23. Added support for CRLF line endings as well as CR and LF. As well as the
1170     default being selectable at build time, it can now be changed at runtime
1171     via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1172     specify that it is scanning data with non-default line endings.
1174     24. Changed the definition of CXXLINK to make it agree with the definition of
1175     LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1177     25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1178     recursions. This makes a big different to stack usage for some patterns.
1180     26. If a subpattern containing a named recursion or subroutine reference such
1181     as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1182     the space required for the compiled pattern went wrong and gave too small a
1183     value. Depending on the environment, this could lead to "Failed: internal
1184     error: code overflow at offset 49" or "glibc detected double free or
1185     corruption" errors.
1187     27. Applied patches from Google (a) to support the new newline modes and (b) to
1188     advance over multibyte UTF-8 characters in GlobalReplace.
1190     28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1191     difference for some implementation of PCRE in some Windows version.
1193     29. Added some extra testing facilities to pcretest:
1195     \q<number> in a data line sets the "match limit" value
1196     \Q<number> in a data line sets the "match recursion limt" value
1197     -S <number> sets the stack size, where <number> is in megabytes
1199     The -S option isn't available for Windows.
1202 nigel 89 Version 6.6 06-Feb-06
1203     ---------------------
1205     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1206     in pcreposix.h. I have copied the definition from pcre.h.
1208     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1209     because pcre.h is no longer a built file.
1211     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1212     not normally included in the compiled code.
1215 nigel 87 Version 6.5 01-Feb-06
1216     ---------------------
1218     1. When using the partial match feature with pcre_dfa_exec(), it was not
1219     anchoring the second and subsequent partial matches at the new starting
1220     point. This could lead to incorrect results. For example, with the pattern
1221     /1234/, partially matching against "123" and then "a4" gave a match.
1223     2. Changes to pcregrep:
1225     (a) All non-match returns from pcre_exec() were being treated as failures
1226     to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
1227     error message is output. Some extra information is given for the
1229     probably the only errors that are likely to be caused by users (by
1230     specifying a regex that has nested indefinite repeats, for instance).
1231     If there are more than 20 of these errors, pcregrep is abandoned.
1233     (b) A binary zero was treated as data while matching, but terminated the
1234     output line if it was written out. This has been fixed: binary zeroes
1235     are now no different to any other data bytes.
1237     (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
1238     used to set a locale for matching. The --locale=xxxx long option has
1239     been added (no short equivalent) to specify a locale explicitly on the
1240     pcregrep command, overriding the environment variables.
1242     (d) When -B was used with -n, some line numbers in the output were one less
1243     than they should have been.
1245     (e) Added the -o (--only-matching) option.
1247     (f) If -A or -C was used with -c (count only), some lines of context were
1248     accidentally printed for the final match.
1250     (g) Added the -H (--with-filename) option.
1252     (h) The combination of options -rh failed to suppress file names for files
1253     that were found from directory arguments.
1255     (i) Added the -D (--devices) and -d (--directories) options.
1257     (j) Added the -F (--fixed-strings) option.
1259     (k) Allow "-" to be used as a file name for -f as well as for a data file.
1261     (l) Added the --colo(u)r option.
1263     (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
1264     is not present by default.
1266     3. A nasty bug was discovered in the handling of recursive patterns, that is,
1267     items such as (?R) or (?1), when the recursion could match a number of
1268     alternatives. If it matched one of the alternatives, but subsequently,
1269     outside the recursion, there was a failure, the code tried to back up into
1270     the recursion. However, because of the way PCRE is implemented, this is not
1271     possible, and the result was an incorrect result from the match.
1273     In order to prevent this happening, the specification of recursion has
1274     been changed so that all such subpatterns are automatically treated as
1275     atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
1277     4. I had overlooked the fact that, in some locales, there are characters for
1278     which isalpha() is true but neither isupper() nor islower() are true. In
1279     the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
1280     and ordfeminine) are like this. This affected the treatment of \w and \W
1281     when they appeared in character classes, but not when they appeared outside
1282     a character class. The bit map for "word" characters is now created
1283     separately from the results of isalnum() instead of just taking it from the
1284     upper, lower, and digit maps. (Plus the underscore character, of course.)
1286     5. The above bug also affected the handling of POSIX character classes such as
1287     [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
1288     permanent tables. Instead, the bit maps for such a class were previously
1289     created as the appropriate unions of the upper, lower, and digit bitmaps.
1290     Now they are created by subtraction from the [[:word:]] class, which has
1291     its own bitmap.
1293     6. The [[:blank:]] character class matches horizontal, but not vertical space.
1294     It is created by subtracting the vertical space characters (\x09, \x0a,
1295     \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
1296     subtraction was done in the overall bitmap for a character class, meaning
1297     that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
1298     be recognized. This bug has been fixed.
1300     7. Patches from the folks at Google:
1302     (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
1303     real life, but is still worth protecting against".
1305     (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
1306     regular expressions".
1308     (c) pcre_scanner.cc: avoid use of std::count() because not all systems
1309     have it.
1311     (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
1312     "configure" and the latter not, in order to fix a problem somebody had
1313     with compiling the Arg class on HP-UX.
1315     (e) Improve the error-handling of the C++ wrapper a little bit.
1317     (f) New tests for checking recursion limiting.
1319     8. The pcre_memmove() function, which is used only if the environment does not
1320     have a standard memmove() function (and is therefore rarely compiled),
1321     contained two bugs: (a) use of int instead of size_t, and (b) it was not
1322     returning a result (though PCRE never actually uses the result).
1324     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
1325     large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
1326     returned instead of calling malloc() with an overflowing number that would
1327     most likely cause subsequent chaos.
1329     10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
1331     11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
1332     with this option is matched, the nmatch and pmatch options of regexec() are
1333     ignored.
1335     12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
1336     provided in case anyone wants to the the POSIX interface with UTF-8
1337     strings.
1339     13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
1340     C++ linking (needed for some HP-UX environments).
1342     14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
1343     (unused parameter) and in the pcre_printint() function (omitted "default"
1344     switch label when the default is to do nothing).
1346     15. Added some code to make it possible, when PCRE is compiled as a C++
1347     library, to replace subject pointers for pcre_exec() with a smart pointer
1348     class, thus making it possible to process discontinuous strings.
1350     16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
1351     much the same function. They were added by different people who were trying
1352     to make PCRE easy to compile on non-Unix systems. It has been suggested
1353     that PCRE_EXPORT be abolished now that there is more automatic apparatus
1354     for compiling on Windows systems. I have therefore replaced it with
1355     PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
1356     defaults to "extern" for C or "extern C" for C++, which works fine on
1357     Unix-like systems. It is now possible to override the value of PCRE_DATA_
1358     SCOPE with something explicit in config.h. In addition:
1360     (a) pcreposix.h still had just "extern" instead of either of these macros;
1361     I have replaced it with PCRE_DATA_SCOPE.
1363     (b) Functions such as _pcre_xclass(), which are internal to the library,
1364     but external in the C sense, all had PCRE_EXPORT in their definitions.
1365     This is apparently wrong for the Windows case, so I have removed it.
1366     (It makes no difference on Unix-like systems.)
1368     17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
1369     of recursive calls to match(). This is different to MATCH_LIMIT because
1370     that limits the total number of calls to match(), not all of which increase
1371     the depth of recursion. Limiting the recursion depth limits the amount of
1372     stack (or heap if NO_RECURSE is set) that is used. The default can be set
1373     when PCRE is compiled, and changed at run time. A patch from Google adds
1374     this functionality to the C++ interface.
1376     18. Changes to the handling of Unicode character properties:
1378     (a) Updated the table to Unicode 4.1.0.
1380     (b) Recognize characters that are not in the table as "Cn" (undefined).
1382     (c) I revised the way the table is implemented to a much improved format
1383     which includes recognition of ranges. It now supports the ranges that
1384     are defined in UnicodeData.txt, and it also amalgamates other
1385     characters into ranges. This has reduced the number of entries in the
1386     table from around 16,000 to around 3,000, thus reducing its size
1387     considerably. I realized I did not need to use a tree structure after
1388     all - a binary chop search is just as efficient. Having reduced the
1389     number of entries, I extended their size from 6 bytes to 8 bytes to
1390     allow for more data.
1392     (d) Added support for Unicode script names via properties such as \p{Han}.
1394     19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
1395     matching that character.
1397     20. When matching a repeated Unicode property with a minimum greater than zero,
1398     (for example \pL{2,}), PCRE could look past the end of the subject if it
1399     reached it while seeking the minimum number of characters. This could
1400     happen only if some of the characters were more than one byte long, because
1401     there is a check for at least the minimum number of bytes.
1403     21. Refactored the implementation of \p and \P so as to be more general, to
1404     allow for more different types of property in future. This has changed the
1405     compiled form incompatibly. Anybody with saved compiled patterns that use
1406     \p or \P will have to recompile them.
1408     22. Added "Any" and "L&" to the supported property types.
1410     23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
1411     but give a compile time error if the value is greater than 0xff.
1413     24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
1414     accidentally not being installed or uninstalled.
1416     25. The pcre.h file was built from pcre.h.in, but the only changes that were
1417     made were to insert the current release number. This seemed silly, because
1418     it made things harder for people building PCRE on systems that don't run
1419     "configure". I have turned pcre.h into a distributed file, no longer built
1420     by "configure", with the version identification directly included. There is
1421     no longer a pcre.h.in file.
1423     However, this change necessitated a change to the pcre-config script as
1424     well. It is built from pcre-config.in, and one of the substitutions was the
1425     release number. I have updated configure.ac so that ./configure now finds
1426     the release number by grepping pcre.h.
1428     26. Added the ability to run the tests under valgrind.
1431 nigel 85 Version 6.4 05-Sep-05
1432     ---------------------
1434     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
1435     "--" to be printed when multiple files were scanned, even when none of the
1436     -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
1437     consider it to be a bug, and have restored the previous behaviour.
1439     2. A couple of code tidies to get rid of compiler warnings.
1441     3. The pcretest program used to cheat by referring to symbols in the library
1442     whose names begin with _pcre_. These are internal symbols that are not
1443     really supposed to be visible externally, and in some environments it is
1444     possible to suppress them. The cheating is now confined to including
1445     certain files from the library's source, which is a bit cleaner.
1447     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
1448     file's purpose clearer.
1450     5. Reorganized pcre_ucp_findchar().
1453 nigel 83 Version 6.3 15-Aug-05
1454     ---------------------
1456     1. The file libpcre.pc.in did not have general read permission in the tarball.
1458     2. There were some problems when building without C++ support:
1460     (a) If C++ support was not built, "make install" and "make test" still
1461     tried to test it.
1463     (b) There were problems when the value of CXX was explicitly set. Some
1464     changes have been made to try to fix these, and ...
1466     (c) --disable-cpp can now be used to explicitly disable C++ support.
1468     (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
1469     backslash in a target when C++ was disabled. This confuses some
1470     versions of "make", apparently. Using an intermediate variable solves
1471     this. (Same for CPP_LOBJ.)
1473     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
1474     (non-Windows) now includes $(CFLAGS) because these flags are sometimes
1475     necessary on certain architectures.
1477     4. Added a setting of -export-symbols-regex to the link command to remove
1478     those symbols that are exported in the C sense, but actually are local
1479     within the library, and not documented. Their names all begin with
1480     "_pcre_". This is not a perfect job, because (a) we have to except some
1481     symbols that pcretest ("illegally") uses, and (b) the facility isn't always
1482     available (and never for static libraries). I have made a note to try to
1483     find a way round (a) in the future.
1486 nigel 81 Version 6.2 01-Aug-05
1487     ---------------------
1489     1. There was no test for integer overflow of quantifier values. A construction
1490     such as {1111111111111111} would give undefined results. What is worse, if
1491     a minimum quantifier for a parenthesized subpattern overflowed and became
1492     negative, the calculation of the memory size went wrong. This could have
1493     led to memory overwriting.
1495     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
1497     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
1498     operating environments where this matters.
1500     4. Applied Giuseppe Maxia's patch to add additional features for controlling
1501     PCRE options from within the C++ wrapper.
1503     5. Named capturing subpatterns were not being correctly counted when a pattern
1504     was compiled. This caused two problems: (a) If there were more than 100
1505     such subpatterns, the calculation of the memory needed for the whole
1506     compiled pattern went wrong, leading to an overflow error. (b) Numerical
1507     back references of the form \12, where the number was greater than 9, were
1508     not recognized as back references, even though there were sufficient
1509     previous subpatterns.
1511     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
1512     versions of gcc, e.g. 2.95.4.
1515 nigel 79 Version 6.1 21-Jun-05
1516     ---------------------
1518     1. There was one reference to the variable "posix" in pcretest.c that was not
1519     surrounded by "#if !defined NOPOSIX".
1521     2. Make it possible to compile pcretest without DFA support, UTF8 support, or
1522     the cross-check on the old pcre_info() function, for the benefit of the
1523     cut-down version of PCRE that is currently imported into Exim.
1525     3. A (silly) pattern starting with (?i)(?-i) caused an internal space
1526     allocation error. I've done the easy fix, which wastes 2 bytes for sensible
1527     patterns that start (?i) but I don't think that matters. The use of (?i) is
1528     just an example; this all applies to the other options as well.
1530     4. Since libtool seems to echo the compile commands it is issuing, the output
1531     from "make" can be reduced a bit by putting "@" in front of each libtool
1532     compile command.
1534     5. Patch from the folks at Google for configure.in to be a bit more thorough
1535     in checking for a suitable C++ installation before trying to compile the
1536     C++ stuff. This should fix a reported problem when a compiler was present,
1537     but no suitable headers.
1539     6. The man pages all had just "PCRE" as their title. I have changed them to
1540     be the relevant file name. I have also arranged that these names are
1541     retained in the file doc/pcre.txt, which is a concatenation in text format
1542     of all the man pages except the little individual ones for each function.
1544     7. The NON-UNIX-USE file had not been updated for the different set of source
1545     files that come with release 6. I also added a few comments about the C++
1546     wrapper.
1549 nigel 77 Version 6.0 07-Jun-05
1550     ---------------------
1552     1. Some minor internal re-organization to help with my DFA experiments.
1554     2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
1555     didn't matter for the library itself when fully configured, but did matter
1556     when compiling without UCP support, or within Exim, where the ucp files are
1557     not imported.
1559     3. Refactoring of the library code to split up the various functions into
1560     different source modules. The addition of the new DFA matching code (see
1561     below) to a single monolithic source would have made it really too
1562     unwieldy, quite apart from causing all the code to be include in a
1563     statically linked application, when only some functions are used. This is
1564     relevant even without the DFA addition now that patterns can be compiled in
1565     one application and matched in another.
1567     The downside of splitting up is that there have to be some external
1568     functions and data tables that are used internally in different modules of
1569     the library but which are not part of the API. These have all had their
1570     names changed to start with "_pcre_" so that they are unlikely to clash
1571     with other external names.
1573     4. Added an alternate matching function, pcre_dfa_exec(), which matches using
1574     a different (DFA) algorithm. Although it is slower than the original
1575     function, it does have some advantages for certain types of matching
1576     problem.
1578     5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
1579     including restarting after a partial match.
1581     6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
1582     defined when compiling for Windows was sent to me. I have put it into the
1583     code, though I have no means of testing or verifying it.
1585     7. Added the pcre_refcount() auxiliary function.
1587     8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
1588     match before or at the first newline in the subject string. In pcretest,
1589     the /f option on a pattern can be used to set this.
1591     9. A repeated \w when used in UTF-8 mode with characters greater than 256
1592     would behave wrongly. This has been present in PCRE since release 4.0.
1594     10. A number of changes to the pcregrep command:
1596     (a) Refactored how -x works; insert ^(...)$ instead of setting
1597     PCRE_ANCHORED and checking the length, in preparation for adding
1598     something similar for -w.
1600     (b) Added the -w (match as a word) option.
1602     (c) Refactored the way lines are read and buffered so as to have more
1603     than one at a time available.
1605     (d) Implemented a pcregrep test script.
1607     (e) Added the -M (multiline match) option. This allows patterns to match
1608     over several lines of the subject. The buffering ensures that at least
1609     8K, or the rest of the document (whichever is the shorter) is available
1610     for matching (and similarly the previous 8K for lookbehind assertions).
1612     (f) Changed the --help output so that it now says
1614     -w, --word-regex(p)
1616     instead of two lines, one with "regex" and the other with "regexp"
1617     because that confused at least one person since the short forms are the
1618     same. (This required a bit of code, as the output is generated
1619     automatically from a table. It wasn't just a text change.)
1621     (g) -- can be used to terminate pcregrep options if the next thing isn't an
1622     option but starts with a hyphen. Could be a pattern or a path name
1623     starting with a hyphen, for instance.
1625     (h) "-" can be given as a file name to represent stdin.
1627     (i) When file names are being printed, "(standard input)" is used for
1628     the standard input, for compatibility with GNU grep. Previously
1629     "<stdin>" was used.
1631     (j) The option --label=xxx can be used to supply a name to be used for
1632     stdin when file names are being printed. There is no short form.
1634     (k) Re-factored the options decoding logic because we are going to add
1635     two more options that take data. Such options can now be given in four
1636     different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
1638     (l) Added the -A, -B, and -C options for requesting that lines of context
1639     around matches be printed.
1641     (m) Added the -L option to print the names of files that do not contain
1642     any matching lines, that is, the complement of -l.
1644     (n) The return code is 2 if any file cannot be opened, but pcregrep does
1645     continue to scan other files.
1647     (o) The -s option was incorrectly implemented. For compatibility with other
1648     greps, it now suppresses the error message for a non-existent or non-
1649     accessible file (but not the return code). There is a new option called
1650     -q that suppresses the output of matching lines, which was what -s was
1651     previously doing.
1653     (p) Added --include and --exclude options to specify files for inclusion
1654     and exclusion when recursing.
1656     11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
1657     Hopefully, it now does.
1659     12. Missing cast in pcre_study().
1661     13. Added an "uninstall" target to the makefile.
1663     14. Replaced "extern" in the function prototypes in Makefile.in with
1664     "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
1665     world, but is set differently for Windows.
1667     15. Added a second compiling function called pcre_compile2(). The only
1668     difference is that it has an extra argument, which is a pointer to an
1669     integer error code. When there is a compile-time failure, this is set
1670     non-zero, in addition to the error test pointer being set to point to an
1671     error message. The new argument may be NULL if no error number is required
1672     (but then you may as well call pcre_compile(), which is now just a
1673     wrapper). This facility is provided because some applications need a
1674     numeric error indication, but it has also enabled me to tidy up the way
1675     compile-time errors are handled in the POSIX wrapper.
1677     16. Added VPATH=.libs to the makefile; this should help when building with one
1678     prefix path and installing with another. (Or so I'm told by someone who
1679     knows more about this stuff than I do.)
1681     17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
1682     passes PCRE_DOTALL to the pcre_compile() function, making the "." character
1683     match everything, including newlines. This is not POSIX-compatible, but
1684     somebody wanted the feature. From pcretest it can be activated by using
1685     both the P and the s flags.
1687     18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
1689     19. libpcre.pc was being incorrectly installed as executable.
1691     20. A couple of places in pcretest check for end-of-line by looking for '\n';
1692     it now also looks for '\r' so that it will work unmodified on Windows.
1694     21. Added Google's contributed C++ wrapper to the distribution.
1696     22. Added some untidy missing memory free() calls in pcretest, to keep
1697     Electric Fence happy when testing.
1701 nigel 75 Version 5.0 13-Sep-04
1702     ---------------------
1704     1. Internal change: literal characters are no longer packed up into items
1705     containing multiple characters in a single byte-string. Each character
1706     is now matched using a separate opcode. However, there may be more than one
1707     byte in the character in UTF-8 mode.
1709     2. The pcre_callout_block structure has two new fields: pattern_position and
1710     next_item_length. These contain the offset in the pattern to the next match
1711     item, and its length, respectively.
1713     3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
1714     insertion of callouts before each pattern item. Added the /C option to
1715     pcretest to make use of this.
1717     4. On the advice of a Windows user, the lines
1719     #if defined(_WIN32) || defined(WIN32)
1720     _setmode( _fileno( stdout ), 0x8000 );
1721     #endif /* defined(_WIN32) || defined(WIN32) */
1723     have been added to the source of pcretest. This apparently does useful
1724     magic in relation to line terminators.
1726     5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
1727     for the benefit of those environments where the "b" makes a difference.
1729     6. The icc compiler has the same options as gcc, but "configure" doesn't seem
1730     to know about it. I have put a hack into configure.in that adds in code
1731     to set GCC=yes if CC=icc. This seems to end up at a point in the
1732     generated configure script that is early enough to affect the setting of
1733     compiler options, which is what is needed, but I have no means of testing
1734     whether it really works. (The user who reported this had patched the
1735     generated configure script, which of course I cannot do.)
1737     LATER: After change 22 below (new libtool files), the configure script
1738     seems to know about icc (and also ecc). Therefore, I have commented out
1739     this hack in configure.in.
1741     7. Added support for pkg-config (2 patches were sent in).
1743     8. Negated POSIX character classes that used a combination of internal tables
1744     were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
1745     [[:^ascii]]. Typically, they would match almost any characters. The other
1746     POSIX classes were not broken in this way.
1748     9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
1749     to find the match, as PCRE was deluded into thinking that the match had to
1750     start at the start point or following a newline. The same bug applied to
1751     patterns with negative forward assertions or any backward assertions
1752     preceding ".*" at the start, unless the pattern required a fixed first
1753     character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
1755     10. In UTF-8 mode, when moving forwards in the subject after a failed match
1756     starting at the last subject character, bytes beyond the end of the subject
1757     string were read.
1759     11. Renamed the variable "class" as "classbits" to make life easier for C++
1760     users. (Previously there was a macro definition, but it apparently wasn't
1761     enough.)
1763     12. Added the new field "tables" to the extra data so that tables can be passed
1764     in at exec time, or the internal tables can be re-selected. This allows
1765     a compiled regex to be saved and re-used at a later time by a different
1766     program that might have everything at different addresses.
1768     13. Modified the pcre-config script so that, when run on Solaris, it shows a
1769     -R library as well as a -L library.
1771     14. The debugging options of pcretest (-d on the command line or D on a
1772     pattern) showed incorrect output for anything following an extended class
1773     that contained multibyte characters and which was followed by a quantifier.
1775     15. Added optional support for general category Unicode character properties
1776     via the \p, \P, and \X escapes. Unicode property support implies UTF-8
1777     support. It adds about 90K to the size of the library. The meanings of the
1778     inbuilt class escapes such as \d and \s have NOT been changed.
1780     16. Updated pcredemo.c to include calls to free() to release the memory for the
1781     compiled pattern.
1783     17. The generated file chartables.c was being created in the source directory
1784     instead of in the building directory. This caused the build to fail if the
1785     source directory was different from the building directory, and was
1786     read-only.
1788     18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
1789     file. No doubt somebody will tell me if they don't make sense... Also added
1790     Dan Mooney's comments about building on OpenVMS.
1792     19. Added support for partial matching via the PCRE_PARTIAL option for
1793     pcre_exec() and the \P data escape in pcretest.
1795     20. Extended pcretest with 3 new pattern features:
1797     (i) A pattern option of the form ">rest-of-line" causes pcretest to
1798     write the compiled pattern to the file whose name is "rest-of-line".
1799     This is a straight binary dump of the data, with the saved pointer to
1800     the character tables forced to be NULL. The study data, if any, is
1801     written too. After writing, pcretest reads a new pattern.
1803     (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
1804     compiled pattern from the given file. There must not be any
1805     occurrences of "<" in the file name (pretty unlikely); if there are,
1806     pcretest will instead treat the initial "<" as a pattern delimiter.
1807     After reading in the pattern, pcretest goes on to read data lines as
1808     usual.
1810     (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
1811     and 16-bit fields in a compiled pattern, to simulate a pattern that
1812     was compiled on a host of opposite endianness.
1814     21. The pcre-exec() function can now cope with patterns that were compiled on
1815     hosts of opposite endianness, with this restriction:
1817     As for any compiled expression that is saved and used later, the tables
1818     pointer field cannot be preserved; the extra_data field in the arguments
1819     to pcre_exec() should be used to pass in a tables address if a value
1820     other than the default internal tables were used at compile time.
1822     22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
1823     now diagnosed as an error. Previously, most of the time, a negative number
1824     would have been treated as zero, but if in addition "ovector" was passed as
1825     NULL, a crash could occur.
1827     23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
1828     new versions from the libtool 1.5 distribution (the last one is a copy of
1829     a file called libtool.m4). This seems to have fixed the need to patch
1830     "configure" to support Darwin 1.3 (which I used to do). However, I still
1831     had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
1832     workstation).
1834     24. Changed the PCRE licence to be the more standard "BSD" licence.
1837 nigel 73 Version 4.5 01-Dec-03
1838     ---------------------
1840     1. There has been some re-arrangement of the code for the match() function so
1841     that it can be compiled in a version that does not call itself recursively.
1842     Instead, it keeps those local variables that need separate instances for
1843     each "recursion" in a frame on the heap, and gets/frees frames whenever it
1844     needs to "recurse". Keeping track of where control must go is done by means
1845     of setjmp/longjmp. The whole thing is implemented by a set of macros that
1846     hide most of the details from the main code, and operates only if
1847     NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
1848     "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
1849     operating.
1851     To make it easier for callers to provide specially tailored get/free
1852     functions for this usage, two new functions, pcre_stack_malloc, and
1853     pcre_stack_free, are used. They are always called in strict stacking order,
1854     and the size of block requested is always the same.
1856     The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
1857     PCRE has been compiled to use the stack or the heap for recursion. The
1858     -C option of pcretest uses this to show which version is compiled.
1860     A new data escape \S, is added to pcretest; it causes the amounts of store
1861     obtained and freed by both kinds of malloc/free at match time to be added
1862     to the output.
1864     2. Changed the locale test to use "fr_FR" instead of "fr" because that's
1865     what's available on my current Linux desktop machine.
1867     3. When matching a UTF-8 string, the test for a valid string at the start has
1868     been extended. If start_offset is not zero, PCRE now checks that it points
1869     to a byte that is the start of a UTF-8 character. If not, it returns
1870     PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
1871     this is necessary because there may be backward assertions in the pattern.
1872     When matching the same subject several times, it may save resources to use
1873     PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
1875     4. The code for checking the validity of UTF-8 strings has been tightened so
1876     that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
1877     containing "overlong sequences".
1879     5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
1880     I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
1881     should have been "&", but it just so happened that all the cases this let
1882     through by mistake were picked up later in the function.
1884     6. I had used a variable called "isblank" - this is a C99 function, causing
1885     some compilers to warn. To avoid this, I renamed it (as "blankclass").
1887     7. Cosmetic: (a) only output another newline at the end of pcretest if it is
1888     prompting; (b) run "./pcretest /dev/null" at the start of the test script
1889     so the version is shown; (c) stop "make test" echoing "./RunTest".
1891     8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
1893     9. The prototype for memmove() for systems that don't have it was using
1894     size_t, but the inclusion of the header that defines size_t was later. I've
1895     moved the #includes for the C headers earlier to avoid this.
1897     10. Added some adjustments to the code to make it easier to compiler on certain
1898     special systems:
1900     (a) Some "const" qualifiers were missing.
1901     (b) Added the macro EXPORT before all exported functions; by default this
1902     is defined to be empty.
1903     (c) Changed the dftables auxiliary program (that builds chartables.c) so
1904     that it reads its output file name as an argument instead of writing
1905     to the standard output and assuming this can be redirected.
1907     11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
1908     class containing characters with values greater than 255, PCRE compilation
1909     went into a loop.
1911     12. A recursive reference to a subpattern that was within another subpattern
1912     that had a minimum quantifier of zero caused PCRE to crash. For example,
1913     (x(y(?2))z)? provoked this bug with a subject that got as far as the
1914     recursion. If the recursively-called subpattern itself had a zero repeat,
1915     that was OK.
1917     13. In pcretest, the buffer for reading a data line was set at 30K, but the
1918     buffer into which it was copied (for escape processing) was still set at
1919     1024, so long lines caused crashes.
1921     14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
1922     "internal error: code overflow...". This applied to any character class
1923     that was followed by a possessive quantifier.
1925     15. Modified the Makefile to add libpcre.la as a prerequisite for
1926     libpcreposix.la because I was told this is needed for a parallel build to
1927     work.
1929     16. If a pattern that contained .* following optional items at the start was
1930     studied, the wrong optimizing data was generated, leading to matching
1931     errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
1932     matching string must start with a or b or c. The correct conclusion for
1933     this pattern is that a match can start with any character.
1936 nigel 71 Version 4.4 13-Aug-03
1937     ---------------------
1939     1. In UTF-8 mode, a character class containing characters with values between
1940     127 and 255 was not handled correctly if the compiled pattern was studied.
1941     In fixing this, I have also improved the studying algorithm for such
1942     classes (slightly).
1944     2. Three internal functions had redundant arguments passed to them. Removal
1945     might give a very teeny performance improvement.
1947     3. Documentation bug: the value of the capture_top field in a callout is *one
1948     more than* the number of the hightest numbered captured substring.
1950     4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
1951     in incorrectly linking with a previously installed version. They now link
1952     explicitly with libpcre.la.
1954     5. configure.in no longer needs to recognize Cygwin specially.
1956     6. A problem in pcre.in for Windows platforms is fixed.
1958     7. If a pattern was successfully studied, and the -d (or /D) flag was given to
1959     pcretest, it used to include the size of the study block as part of its
1960     output. Unfortunately, the structure contains a field that has a different
1961     size on different hardware architectures. This meant that the tests that
1962     showed this size failed. As the block is currently always of a fixed size,
1963     this information isn't actually particularly useful in pcretest output, so
1964     I have just removed it.
1966     8. Three pre-processor statements accidentally did not start in column 1.
1967     Sadly, there are *still* compilers around that complain, even though
1968     standard C has not required this for well over a decade. Sigh.
1970     9. In pcretest, the code for checking callouts passed small integers in the
1971     callout_data field, which is a void * field. However, some picky compilers
1972     complained about the casts involved for this on 64-bit systems. Now
1973     pcretest passes the address of the small integer instead, which should get
1974     rid of the warnings.
1976     10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
1977     both compile and run time, and gives an error if an invalid UTF-8 sequence
1978     is found. There is a option for disabling this check in cases where the
1979     string is known to be correct and/or the maximum performance is wanted.
1981     11. In response to a bug report, I changed one line in Makefile.in from
1983     -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
1984     to
1985     -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
1987     to look similar to other lines, but I have no way of telling whether this
1988     is the right thing to do, as I do not use Windows. No doubt I'll get told
1989     if it's wrong...
1992 nigel 69 Version 4.3 21-May-03
1993     ---------------------
1995     1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
1996     Makefile.
1998     2. Some refactoring to improve the quality of the code:
2000     (i) The utf8_table... variables are now declared "const".
2002     (ii) The code for \cx, which used the "case flipping" table to upper case
2003     lower case letters, now just substracts 32. This is ASCII-specific,
2004     but the whole concept of \cx is ASCII-specific, so it seems
2005     reasonable.
2007     (iii) PCRE was using its character types table to recognize decimal and
2008     hexadecimal digits in the pattern. This is silly, because it handles
2009     only 0-9, a-f, and A-F, but the character types table is locale-
2010     specific, which means strange things might happen. A private
2011     table is now used for this - though it costs 256 bytes, a table is
2012     much faster than multiple explicit tests. Of course, the standard
2013     character types table is still used for matching digits in subject
2014     strings against \d.
2016     (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
2017     ending in _t are). So I've renamed it as ESC_tee.
2019     3. The first argument for regexec() in the POSIX wrapper should have been
2020     defined as "const".
2022     4. Changed pcretest to use malloc() for its buffers so that they can be
2023     Electric Fenced for debugging.
2025     5. There were several places in the code where, in UTF-8 mode, PCRE would try
2026     to read one or more bytes before the start of the subject string. Often this
2027     had no effect on PCRE's behaviour, but in some circumstances it could
2028     provoke a segmentation fault.
2030     6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
2031     to try to read one or more bytes before the start of the subject string.
2033     7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
2034     UTF-8 support could misbehave in various ways if the subject string
2035     contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
2036     area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
2037     back over UTF-8 characters.)
2040 nigel 67 Version 4.2 14-Apr-03
2041     ---------------------
2043     1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
2045     2. Changes to the building process, supplied by Ronald Landheer-Cieslak
2046     [ON_WINDOWS]: new variable, "#" on non-Windows platforms
2047     [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
2048     [WIN_PREFIX]: new variable, "cyg" for Cygwin
2049     * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
2050     and BUILD_EXEEXT
2051     Note: automatic setting of the BUILD variables is not yet working
2052     set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
2053     compile-time but not at link-time
2054     [LINK]: use for linking executables only
2055     make different versions for Windows and non-Windows
2056     [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
2057     libraries
2058     [LINK_FOR_BUILD]: new variable
2059     [OBJEXT]: use throughout
2060     [EXEEXT]: use throughout
2061     <winshared>: new target
2062     <wininstall>: new target
2063     <dftables.o>: use native compiler
2064     <dftables>: use native linker
2065     <install>: handle Windows platform correctly
2066     <clean>: ditto
2067     <check>: ditto
2068     copy DLL to top builddir before testing
2070     As part of these changes, -no-undefined was removed again. This was reported
2071     to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
2072     in any case.
2074     3. Some tidies to get rid of compiler warnings:
2076     . In the match_data structure, match_limit was an unsigned long int, whereas
2077     match_call_count was an int. I've made them both unsigned long ints.
2079     . In pcretest the fact that a const uschar * doesn't automatically cast to
2080     a void * provoked a warning.
2082     . Turning on some more compiler warnings threw up some "shadow" variables
2083     and a few more missing casts.
2085     4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
2086     option, a class that contained a single character with a value between 128
2087     and 255 (e.g. /[\xFF]/) caused PCRE to crash.
2089     5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
2090     option, a class that contained several characters, but with at least one
2091     whose value was between 128 and 255 caused PCRE to crash.
2094 nigel 65 Version 4.1 12-Mar-03
2095     ---------------------
2096 nigel 63
2097 nigel 65 1. Compiling with gcc -pedantic found a couple of places where casts were
2098     needed, and a string in dftables.c that was longer than standard compilers are
2099     required to support.
2101     2. Compiling with Sun's compiler found a few more places where the code could
2102     be tidied up in order to avoid warnings.
2104     3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
2105     first of these names is deprecated in the latest Autoconf in favour of the name
2106     CC_FOR_BUILD, because "host" is typically used to mean the system on which the
2107     compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
2108     analogy I have changed it to CFLAGS_FOR_BUILD.
2110     4. Added -no-undefined to the linking command in the Makefile, because this is
2111     apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
2112     linking step for the pcreposix library.
2114     5. PCRE was failing to diagnose the case of two named groups with the same
2115     name.
2117     6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
2118     literal character that is needed in the subject for a match, and scans along to
2119     ensure that it is present before embarking on the full matching process. This
2120     saves time in cases of nested unlimited repeats that are never going to match.
2121     Problem: the scan can take a lot of time if the subject is very long (e.g.
2122     megabytes), thus penalizing straightforward matches. It is now done only if the
2123     amount of subject to be scanned is less than 1000 bytes.
2125     7. A lesser problem with the same optimization is that it was recording the
2126     first character of an anchored pattern as "needed", thus provoking a search
2127     right along the subject, even when the first match of the pattern was going to
2128     fail. The "needed" character is now not set for anchored patterns, unless it
2129     follows something in the pattern that is of non-fixed length. Thus, it still
2130     fulfils its original purpose of finding quick non-matches in cases of nested
2131     unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
2134     Version 4.0 17-Feb-03
2135     ---------------------
2137 nigel 63 1. If a comment in an extended regex that started immediately after a meta-item
2138     extended to the end of string, PCRE compiled incorrect data. This could lead to
2139     all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
2141     2. Moved to autoconf 2.53 and libtool 1.4.2.
2143     3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
2144     the special perltest8 script is no longer needed - all the tests can be run
2145     from a single perltest script.
2147     4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
2148     by \s. It has now been removed in PCRE. This means it isn't recognized as
2149     whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
2150     class [:space:] *does* include VT, thereby creating a mess.
2152     5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
2153     space and tab.
2155     6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
2156     its new features into the main test script, reducing the number of scripts.
2158     7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
2159     were backward compatible, and made the (?i) apply to the whole pattern, as if
2160     /i were given. Now it behaves more logically, and applies the option setting
2161     only to what follows. PCRE has been changed to follow suit. However, if it
2162     finds options settings right at the start of the pattern, it extracts them into
2163     the global options, as before. Thus, they show up in the info data.
2165     8. Added support for the \Q...\E escape sequence. Characters in between are
2166     treated as literals. This is slightly different from Perl in that $ and @ are
2167     also handled as literals inside the quotes. In Perl, they will cause variable
2168     interpolation. Note the following examples:
2170     Pattern PCRE matches Perl matches
2172     \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
2173     \Qabc\$xyz\E abc\$xyz abc\$xyz
2174     \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
2176     For compatibility with Perl, \Q...\E sequences are recognized inside character
2177     classes as well as outside them.
2179     9. Re-organized 3 code statements in pcretest to avoid "overflow in
2180     floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
2181     (size_t) cast to one statement in pcretest and one in pcreposix to avoid
2182     signed/unsigned warnings.
2184     10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
2185     option for pcretest, so I've replaced it by a simple function that does just
2186     that job.
2188     11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
2189     "pcregrep -".
2191     12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
2192     Java package. This provides some syntactic sugar for simple cases of what my
2193     documentation calls "once-only subpatterns". A pattern such as x*+ is the same
2194     as (?>x*). In other words, if what is inside (?>...) is just a single repeated
2195     item, you can use this simplified notation. Note that only makes sense with
2196     greedy quantifiers. Consequently, the use of the possessive quantifier forces
2197     greediness, whatever the setting of the PCRE_UNGREEDY option.
2199     13. A change of greediness default within a pattern was not taking effect at
2200     the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
2201     subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
2202     was abstracted outside.
2204     14. PCRE now supports the \G assertion. It is true when the current matching
2205     position is at the start point of the match. This differs from \A when the
2206     starting offset is non-zero. Used with the /g option of pcretest (or similar
2207     code), it works in the same way as it does for Perl's /g option. If all
2208     alternatives of a regex begin with \G, the expression is anchored to the start
2209     match position, and the "anchored" flag is set in the compiled expression.
2211     15. Some bugs concerning the handling of certain option changes within patterns
2212     have been fixed. These applied to options other than (?ims). For example,
2213     "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
2214     been the other way round. Some of this was related to change 7 above.
2216     16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
2217     features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
2218     and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
2219     POSIX classes only within a class (e.g. /[[:alpha:]]/).
2221     17. Added support for Perl's \C escape. This matches one byte, even in UTF8
2222     mode. Unlike ".", it always matches newline, whatever the setting of
2223     PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
2224     assertions. Perl allows it, but it doesn't (in general) work because it can't
2225     calculate the length of the lookbehind. At least, that's the case for Perl
2226     5.8.0 - I've been told they are going to document that it doesn't work in
2227     future.
2229     18. Added an error diagnosis for escapes that PCRE does not support: these are
2230     \L, \l, \N, \P, \p, \U, \u, and \X.
2232     19. Although correctly diagnosing a missing ']' in a character class, PCRE was
2233     reading past the end of the pattern in cases such as /[abcd/.
2235     20. PCRE was getting more memory than necessary for patterns with classes that
2236     contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
2238     21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
2239     compiling PCRE for use with Virtual Pascal.
2241     22. Small fix to the Makefile to make it work properly if the build is done
2242     outside the source tree.
2244     23. Added a new extension: a condition to go with recursion. If a conditional
2245     subpattern starts with (?(R) the "true" branch is used if recursion has
2246     happened, whereas the "false" branch is used only at the top level.
2248     24. When there was a very long string of literal characters (over 255 bytes
2249     without UTF support, over 250 bytes with UTF support), the computation of how
2250     much memory was required could be incorrect, leading to segfaults or other
2251     strange effects.
2253     25. PCRE was incorrectly assuming anchoring (either to start of subject or to
2254     start of line for a non-DOTALL pattern) when a pattern started with (.*) and
2255     there was a subsequent back reference to those brackets. This meant that, for
2256     example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
2257     possible to check for precisely this case. All we can do is abandon the
2258     optimization if .* occurs inside capturing brackets when there are any back
2259     references whatsoever. (See below for a better fix that came later.)
2261     26. The handling of the optimization for finding the first character of a
2262     non-anchored pattern, and for finding a character that is required later in the
2263     match were failing in some cases. This didn't break the matching; it just
2264     failed to optimize when it could. The way this is done has been re-implemented.
2266     27. Fixed typo in error message for invalid (?R item (it said "(?p").
2268     28. Added a new feature that provides some of the functionality that Perl
2269     provides with (?{...}). The facility is termed a "callout". The way it is done
2270     in PCRE is for the caller to provide an optional function, by setting
2271     pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
2272     global variable. By default it is unset, which disables all calling out. To get
2273     the function called, the regex must include (?C) at appropriate points. This
2274     is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
2275     This provides a means of identifying different callout points. When PCRE
2276     reaches such a point in the regex, if pcre_callout has been set, the external
2277     function is called. It is provided with data in a structure called
2278     pcre_callout_block, which is defined in pcre.h. If the function returns 0,
2279     matching continues; if it returns a non-zero value, the match at the current
2280     point fails. However, backtracking will occur if possible. [This was changed
2281     later and other features added - see item 49 below.]
2283     29. pcretest is upgraded to test the callout functionality. It provides a
2284     callout function that displays information. By default, it shows the start of
2285     the match and the current position in the text. There are some new data escapes
2286     to vary what happens:
2288     \C+ in addition, show current contents of captured substrings
2289     \C- do not supply a callout function
2290     \C!n return 1 when callout number n is reached
2291     \C!n!m return 1 when callout number n is reached for the mth time
2293     30. If pcregrep was called with the -l option and just a single file name, it
2294     output "<stdin>" if a match was found, instead of the file name.
2296     31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
2297     slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
2298     pcre_exec(). This saves a malloc/free per call. The default value of
2299     POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
2300     when configuring.
2302     32. The default maximum size of a compiled pattern is 64K. There have been a
2303     few cases of people hitting this limit. The code now uses macros to handle the
2304     storing of links as offsets within the compiled pattern. It defaults to 2-byte
2305     links, but this can be changed to 3 or 4 bytes by --with-link-size when
2306     configuring. Tests 2 and 5 work only with 2-byte links because they output
2307     debugging information about compiled patterns.
2309     33. Internal code re-arrangements:
2311     (a) Moved the debugging function for printing out a compiled regex into
2312     its own source file (printint.c) and used #include to pull it into
2313     pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
2314     separate copies.
2316     (b) Defined the list of op-code names for debugging as a macro in
2317     internal.h so that it is next to the definition of the opcodes.
2319     (c) Defined a table of op-code lengths for simpler skipping along compiled
2320     code. This is again a macro in internal.h so that it is next to the
2321     definition of the opcodes.
2323     34. Added support for recursive calls to individual subpatterns, along the
2324     lines of Robin Houston's patch (but implemented somewhat differently).
2326     35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
2327     allow it to read and process whole directories in Win32. This code was
2328     contributed by Lionel Fourquaux; it has not been tested by me.
2330     36. Added support for named subpatterns. The Python syntax (?P<name>...) is
2331     used to name a group. Names consist of alphanumerics and underscores, and must
2332     be unique. Back references use the syntax (?P=name) and recursive calls use
2333     (?P>name) which is a PCRE extension to the Python extension. Groups still have
2334     numbers. The function pcre_fullinfo() can be used after compilation to extract
2335     a name/number map. There are three relevant calls:
2337     PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
2338     PCRE_INFO_NAMECOUNT yields the number of entries
2339     PCRE_INFO_NAMETABLE yields a pointer to the map.
2341     The map is a vector of fixed-size entries. The size of each entry depends on
2342     the length of the longest name used. The first two bytes of each entry are the
2343     group number, most significant byte first. There follows the corresponding
2344     name, zero terminated. The names are in alphabetical order.
2346     37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
2347     case instead of 255. Making it the same both with and without UTF-8 support
2348     means that the same test output works with both.
2350     38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
2351     calling malloc() with a zero argument.
2353     39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
2354     optimization. I've improved things by keeping a bitmap of backreferences with
2355     numbers 1-31 so that if .* occurs inside capturing brackets that are not in
2356     fact referenced, the optimization can be applied. It is unlikely that a
2357     relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
2358     the match to follow \n) will appear inside brackets with a number greater than
2359     31, but if it does, any back reference > 31 suppresses the optimization.
2361     40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
2362     of disabling numbered capturing parentheses. Any opening parenthesis that is
2363     not followed by ? behaves as if it were followed by ?: but named parentheses
2364     can still be used for capturing (and they will acquire numbers in the usual
2365     way).
2367     41. Redesigned the return codes from the match() function into yes/no/error so
2368     that errors can be passed back from deep inside the nested calls. A malloc
2369     failure while inside a recursive subpattern call now causes the
2370     PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
2372     42. It is now possible to set a limit on the number of times the match()
2373     function is called in a call to pcre_exec(). This facility makes it possible to
2374     limit the amount of recursion and backtracking, though not in a directly
2375     obvious way, because the match() function is used in a number of different
2376     circumstances. The count starts from zero for each position in the subject
2377     string (for non-anchored patterns). The default limit is, for compatibility, a
2378     large number, namely 10 000 000. You can change this in two ways:
2380     (a) When configuring PCRE before making, you can use --with-match-limit=n
2381     to set a default value for the compiled library.
2383     (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
2384     a different value is set. See 45 below.
2386     If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
2388     43. Added a new function pcre_config(int, void *) to enable run-time extraction
2389     of things that can be changed at compile time. The first argument specifies
2390     what is wanted and the second points to where the information is to be placed.
2391     The current list of available information is:
2395     The output is an integer that is set to one if UTF-8 support is available;
2396     otherwise it is set to zero.
2400     The output is an integer that it set to the value of the code that is used for
2401     newline. It is either LF (10) or CR (13).
2405     The output is an integer that contains the number of bytes used for internal
2406     linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
2410     The output is an integer that contains the threshold above which the POSIX
2411     interface uses malloc() for output vectors. See item 31 above.
2415     The output is an unsigned integer that contains the default limit of the number
2416     of match() calls in a pcre_exec() execution. See 42 above.
2418     44. pcretest has been upgraded by the addition of the -C option. This causes it
2419     to extract all the available output from the new pcre_config() function, and to
2420     output it. The program then exits immediately.
2422     45. A need has arisen to pass over additional data with calls to pcre_exec() in
2423     order to support additional features. One way would have been to define
2424     pcre_exec2() (for example) with extra arguments, but this would not have been
2425     extensible, and would also have required all calls to the original function to
2426     be mapped to the new one. Instead, I have chosen to extend the mechanism that
2427     is used for passing in "extra" data from pcre_study().
2429     The pcre_extra structure is now exposed and defined in pcre.h. It currently
2430     contains the following fields:
2432     flags a bitmap indicating which of the following fields are set
2433     study_data opaque data from pcre_study()
2434     match_limit a way of specifying a limit on match() calls for a specific
2435     call to pcre_exec()
2436     callout_data data for callouts (see 49 below)
2438     The flag bits are also defined in pcre.h, and are
2444     The pcre_study() function now returns one of these new pcre_extra blocks, with
2445     the actual study data pointed to by the study_data field, and the
2446     PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
2447     before. That is, this change is entirely upwards-compatible and requires no
2448     change to existing code.
2450     If you want to pass in additional data to pcre_exec(), you can either place it
2451     in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
2452     block.
2454     46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
2455     data string contains the escape sequence \M, pcretest calls pcre_exec() several
2456     times with different match limits, until it finds the minimum value needed for
2457     pcre_exec() to complete. The value is then output. This can be instructive; for
2458     most simple matches the number is quite small, but for pathological cases it
2459     gets very large very quickly.
2461     47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
2462     returns the size of the data block pointed to by the study_data field in a
2463     pcre_extra block, that is, the value that was passed as the argument to
2464     pcre_malloc() when PCRE was getting memory in which to place the information
2465     created by pcre_study(). The fourth argument should point to a size_t variable.
2466     pcretest has been extended so that this information is shown after a successful
2467     pcre_study() call when information about the compiled regex is being displayed.
2469     48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
2470     because what follows is always an absolute path. (Later: it turns out that this
2471     is more than cosmetic for MinGW, because it doesn't like empty path
2472     components.)
2474     49. Some changes have been made to the callout feature (see 28 above):
2476     (i) A callout function now has three choices for what it returns:
2478     0 => success, carry on matching
2479     > 0 => failure at this point, but backtrack if possible
2480     < 0 => serious error, return this value from pcre_exec()
2482     Negative values should normally be chosen from the set of PCRE_ERROR_xxx
2483     values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
2484     "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
2485     use by callout functions. It will never be used by PCRE itself.
2487     (ii) The pcre_extra structure (see 45 above) has a void * field called
2488     callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
2489     pcre_callout_block structure has a field of the same name. The contents of
2490     the field passed in the pcre_extra structure are passed to the callout
2491     function in the corresponding field in the callout block. This makes it
2492     easier to use the same callout-containing regex from multiple threads. For
2493     testing, the pcretest program has a new data escape
2495     \C*n pass the number n (may be negative) as callout_data
2497     If the callout function in pcretest receives a non-zero value as
2498     callout_data, it returns that value.
2500     50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
2501     there were some redundant $(CFLAGS) in commands that are now specified as
2502     $(LINK), which already includes $(CFLAGS).
2504     51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
2505     has been compiled with UTF-8 support *and* pcre_compile() has been compiled
2506     with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
2507     one-byte characters throughout. Note that case-insensitive matching applies
2508     only to characters whose values are less than 256. PCRE doesn't support the
2509     notion of cases for higher-valued characters.
2511     (i) A character class whose characters are all within 0-255 is handled as
2512     a bit map, and the map is inverted for negative classes. Previously, a
2513     character > 255 always failed to match such a class; however it should
2514     match if the class was a negative one (e.g. [^ab]). This has been fixed.
2516     (ii) A negated character class with a single character < 255 is coded as
2517     "not this character" (OP_NOT). This wasn't working properly when the test
2518     character was multibyte, either singly or repeated.
2520     (iii) Repeats of multibyte characters are now handled correctly in UTF-8
2521     mode, for example: \x{100}{2,3}.
2523     (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
2524     singly or repeated) now correctly test multibyte characters. However,
2525     PCRE doesn't recognize any characters with values greater than 255 as
2526     digits, spaces, or word characters. Such characters always match \D, \S,
2527     and \W, and never match \d, \s, or \w.
2529     (v) Classes may now contain characters and character ranges with values
2530     greater than 255. For example: [ab\x{100}-\x{400}].
2532     (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
2533     PCRE in UTF-8 mode.
2535     52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
2536     PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
2537     retained for backwards compatibility. (Note that LASTLITERAL is also a byte
2538     value.)
2540     53. The single man page has become too large. I have therefore split it up into
2541     a number of separate man pages. These also give rise to individual HTML pages;
2542     these are now put in a separate directory, and there is an index.html page that
2543     lists them all. Some hyperlinking between the pages has been installed.
2545     54. Added convenience functions for handling named capturing parentheses.
2547     55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
2548     aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
2549     true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
2550     are faulted.
2552     56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
2553     calling configure. These values are used when compiling the dftables.c program
2554     which is run to generate the source of the default character tables. They
2555     default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
2556     you will need to set these values.
2558     57. Updated the building process for Windows DLL, as provided by Fred Cox.
2561     Version 3.9 02-Jan-02
2562 nigel 61 ---------------------
2564     1. A bit of extraneous text had somehow crept into the pcregrep documentation.
2566     2. If --disable-static was given, the building process failed when trying to
2567     build pcretest and pcregrep. (For some reason it was using libtool to compile
2568     them, which is not right, as they aren't part of the library.)
2571 nigel 59 Version 3.8 18-Dec-01
2572     ---------------------
2574     1. The experimental UTF-8 code was completely screwed up. It was packing the
2575     bytes in the wrong order. How dumb can you get?
2578 nigel 57 Version 3.7 29-Oct-01
2579     ---------------------
2581     1. In updating pcretest to check change 1 of version 3.6, I screwed up.
2582     This caused pcretest, when used on the test data, to segfault. Unfortunately,
2583     this didn't happen under Solaris 8, where I normally test things.
2585 nigel 59 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
2586     doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
2587     isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
2588     this fix an hour or so after the initial 3.7 release.)
2589 nigel 57
2590 nigel 59
2591 nigel 55 Version 3.6 23-Oct-01
2592     ---------------------
2594     1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
2595     offsets passed as NULL with zero offset count.
2597     2. The config.guess and config.sub files had not been updated when I moved to
2598     the latest autoconf.
2601 nigel 53 Version 3.5 15-Aug-01
2602     ---------------------
2603 nigel 5
2604 nigel 53 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
2605     had been forgotten.
2607     2. By using declared but undefined structures, we can avoid using "void"
2608     definitions in pcre.h while keeping the internal definitions of the structures
2609     private.
2611     3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
2612     user point of view, this means that both static and shared libraries are built
2613     by default, but this can be individually controlled. More of the work of
2614     handling this static/shared cases is now inside libtool instead of PCRE's make
2615     file.
2617     4. The pcretest utility is now installed along with pcregrep because it is
2618     useful for users (to test regexs) and by doing this, it automatically gets
2619     relinked by libtool. The documentation has been turned into a man page, so
2620     there are now .1, .txt, and .html versions in /doc.
2622     5. Upgrades to pcregrep:
2623     (i) Added long-form option names like gnu grep.
2624     (ii) Added --help to list all options with an explanatory phrase.
2625     (iii) Added -r, --recursive to recurse into sub-directories.
2626     (iv) Added -f, --file to read patterns from a file.
2628     6. pcre_exec() was referring to its "code" argument before testing that
2629     argument for NULL (and giving an error if it was NULL).
2631     7. Upgraded Makefile.in to allow for compiling in a different directory from
2632     the source directory.
2634     8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
2635     options bits, the pointer it was passed was to an int instead of to an unsigned
2636     long int. This mattered only on 64-bit systems.
2638     9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
2639     generated) instead of pcre.in, which it its source. Also made the same change
2640     in several of the .c files.
2642     10. A new release of gcc defines printf() as a macro, which broke pcretest
2643     because it had an ifdef in the middle of a string argument for printf(). Fixed
2644     by using separate calls to printf().
2646     11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
2647     script, to force use of CR or LF instead of \n in the source. On non-Unix
2648     systems, the value can be set in config.h.
2650     12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
2651     absolute limit. Changed the text of the error message to make this clear, and
2652     likewise updated the man page.
2654     13. The limit of 99 on the number of capturing subpatterns has been removed.
2655     The new limit is 65535, which I hope will not be a "real" limit.
2658 nigel 51 Version 3.4 22-Aug-00
2659     ---------------------
2661     1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
2663     2. Diagnose condition (?(0) as an error instead of crashing on matching.
2666 nigel 49 Version 3.3 01-Aug-00
2667     ---------------------
2669     1. If an octal character was given, but the value was greater than \377, it
2670     was not getting masked to the least significant bits, as documented. This could
2671     lead to crashes in some systems.
2673     2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
2674     the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
2676     3. Added the functions pcre_free_substring() and pcre_free_substring_list().
2677     These just pass their arguments on to (pcre_free)(), but they are provided
2678     because some uses of PCRE bind it to non-C systems that can call its functions,
2679     but cannot call free() or pcre_free() directly.
2681     4. Add "make test" as a synonym for "make check". Corrected some comments in
2682     the Makefile.
2684     5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
2685     Makefile.
2687     6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
2688     command called pgrep for grepping around the active processes.
2690     7. Added the beginnings of support for UTF-8 character strings.
2692     8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
2693     RANLIB to ./ltconfig so that they are used by libtool. I think these are all
2694     the relevant ones. (AR is not passed because ./ltconfig does its own figuring
2695     out for the ar command.)
2698 nigel 47 Version 3.2 12-May-00
2699     ---------------------
2701     This is purely a bug fixing release.
2703     1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
2704     of ZA. This was just one example of several cases that could provoke this bug,
2705     which was introduced by change 9 of version 2.00. The code for breaking
2706     infinite loops after an iteration that matches an empty string was't working
2707     correctly.
2709     2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
2710     when matched against abbab (for example). After matching an empty string, it
2711     wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
2712     caused it to match further down the string than it should.
2714     3. The code contained an inclusion of sys/types.h. It isn't clear why this
2715     was there because it doesn't seem to be needed, and it causes trouble on some
2716     systems, as it is not a Standard C header. It has been removed.
2718     4. Made 4 silly changes to the source to avoid stupid compiler warnings that
2719     were reported on the Macintosh. The changes were from
2721     while ((c = *(++ptr)) != 0 && c != '\n');
2722     to
2723     while ((c = *(++ptr)) != 0 && c != '\n') ;
2725     Totally extraordinary, but if that's what it takes...
2727     5. PCRE is being used in one environment where neither memmove() nor bcopy() is
2728     available. Added HAVE_BCOPY and an autoconf test for it; if neither
2729     HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
2730     assumes the way PCRE uses memmove() (always moving upwards).
2732     6. PCRE is being used in one environment where strchr() is not available. There
2733     was only one use in pcre.c, and writing it out to avoid strchr() probably gives
2734     faster code anyway.
2737 nigel 45 Version 3.1 09-Feb-00
2738     ---------------------
2740     The only change in this release is the fixing of some bugs in Makefile.in for
2741     the "install" target:
2743     (1) It was failing to install pcreposix.h.
2745     (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
2748 nigel 43 Version 3.0 01-Feb-00
2749     ---------------------
2750 nigel 41
2751     1. Add support for the /+ modifier to perltest (to output $` like it does in
2752     pcretest).
2754     2. Add support for the /g modifier to perltest.
2756     3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
2757     matches null strings.
2759     4. Fix perltest so that it doesn't do unwanted things when fed an empty
2760     pattern. Perl treats empty patterns specially - it reuses the most recent
2761     pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
2762     effect.
2764     5. The POSIX interface was broken in that it was just handing over the POSIX
2765     captured string vector to pcre_exec(), but (since release 2.00) PCRE has
2766     required a bigger vector, with some working space on the end. This means that
2767     the POSIX wrapper now has to get and free some memory, and copy the results.
2769 nigel 43 6. Added some simple autoconf support, placing the test data and the
2770     documentation in separate directories, re-organizing some of the
2771     information files, and making it build pcre-config (a GNU standard). Also added
2772     libtool support for building PCRE as a shared library, which is now the
2773     default.
2774 nigel 41
2775 nigel 43 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
2776     09 are not valid octal constants. Single digits will be used for minor values
2777     less than 10.
2779     8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
2780     existing programs that set these in the POSIX interface can use PCRE without
2781     modification.
2783     9. Added a new function, pcre_fullinfo() with an extensible interface. It can
2784     return all that pcre_info() returns, plus additional data. The pcre_info()
2785     function is retained for compatibility, but is considered to be obsolete.
2787     10. Added experimental recursion feature (?R) to handle one common case that
2788     Perl 5.6 will be able to do with (?p{...}).
2790     11. Added support for POSIX character classes like [:alpha:], which Perl is
2791     adopting.
2794 nigel 39 Version 2.08 31-Aug-99
2795     ----------------------
2797     1. When startoffset was not zero and the pattern began with ".*", PCRE was not
2798     trying to match at the startoffset position, but instead was moving forward to
2799     the next newline as if a previous match had failed.
2801     2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
2802     and could get into a loop if a null string was matched other than at the start
2803     of the subject.
2805     3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
2806     be distinguished at compile time, and for completeness also added PCRE_DATE.
2808     5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
2809     in GnuWin32 environments.
2812 nigel 37 Version 2.07 29-Jul-99
2813     ----------------------
2815     1. The documentation is now supplied in plain text form and HTML as well as in
2816     the form of man page sources.
2818     2. C++ compilers don't like assigning (void *) values to other pointer types.
2819     In particular this affects malloc(). Although there is no problem in Standard
2820     C, I've put in casts to keep C++ compilers happy.
2822     3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
2823     should be (const char *).
2825     4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
2826     be useful for non-Unix systems who don't want to bother with the POSIX stuff.
2827     However, I haven't made this a standard facility. The documentation doesn't
2828     mention it, and the Makefile doesn't support it.
2830     5. The Makefile now contains an "install" target, with editable destinations at
2831     the top of the file. The pcretest program is not installed.
2833     6. pgrep -V now gives the PCRE version number and date.
2835     7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
2836     causing the entire string to be ignored, instead of just the last character.
2838     8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
2839     non-matching string, it can take a very, very long time, even for strings of
2840     quite modest length, because of the nested recursion. PCRE now does better in
2841     some of these cases. It does this by remembering the last required literal
2842     character in the pattern, and pre-searching the subject to ensure it is present
2843     before running the real match. In other words, it applies a heuristic to detect
2844     some types of certain failure quickly, and in the above example, if presented
2845     with a string that has no trailing " it gives "no match" very quickly.
2847     9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
2848     other alternatives are tried instead.
2851 nigel 35 Version 2.06 09-Jun-99
2852     ----------------------
2854     1. Change pcretest's output for amount of store used to show just the code
2855     space, because the remainder (the data block) varies in size between 32-bit and
2856     64-bit systems.
2858     2. Added an extra argument to pcre_exec() to supply an offset in the subject to
2859     start matching at. This allows lookbehinds to work when searching for multiple
2860     occurrences in a string.
2862     3. Added additional options to pcretest for testing multiple occurrences:
2864     /+ outputs the rest of the string that follows a match
2865     /g loops for multiple occurrences, using the new startoffset argument
2866     /G loops for multiple occurrences by passing an incremented pointer
2868     4. PCRE wasn't doing the "first character" optimization for patterns starting
2869     with \b or \B, though it was doing it for other lookbehind assertions. That is,
2870     it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
2871     the letter 'x'. On long subject strings, this gives a significant speed-up.
2874 nigel 33 Version 2.05 21-Apr-99
2875     ----------------------
2877     1. Changed the type of magic_number from int to long int so that it works
2878     properly on 16-bit systems.
2880     2. Fixed a bug which caused patterns starting with .* not to work correctly
2881     when the subject string contained newline characters. PCRE was assuming
2882     anchoring for such patterns in all cases, which is not correct because .* will
2883     not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
2884     DOTALL is set at top level; otherwise it knows that patterns starting with .*
2885     must be retried after every newline in the subject.
2888 nigel 31 Version 2.04 18-Feb-99
2889     ----------------------
2891     1. For parenthesized subpatterns with repeats whose minimum was zero, the
2892     computation of the store needed to hold the pattern was incorrect (too large).
2893     If such patterns were nested a few deep, this could multiply and become a real
2894     problem.
2896     2. Added /M option to pcretest to show the memory requirement of a specific
2897     pattern. Made -m a synonym of -s (which does this globally) for compatibility.
2899     3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
2900     compiled in such a way that the backtracking after subsequent failure was
2901     pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
2902     ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
2905 nigel 29 Version 2.03 02-Feb-99
2906     ----------------------
2908     1. Fixed typo and small mistake in man page.
2910 nigel 31 2. Added 4th condition (GPL supersedes if conflict) and created separate
2911     LICENCE file containing the conditions.
2912 nigel 29
2913     3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
2914     Perl, that is the internal \ allows the delimiter to be included in the
2915     pattern. Locked out the use of \ as a delimiter. If \ immediately follows
2916     the final delimiter, add \ to the end of the pattern (to test the error).
2918     4. Added the convenience functions for extracting substrings after a successful
2919     match. Updated pcretest to make it able to test these functions.
2922 nigel 27 Version 2.02 14-Jan-99
2923     ----------------------
2925     1. Initialized the working variables associated with each extraction so that
2926     their saving and restoring doesn't refer to uninitialized store.
2928     2. Put dummy code into study.c in order to trick the optimizer of the IBM C
2929     compiler for OS/2 into generating correct code. Apparently IBM isn't going to
2930     fix the problem.
2932     3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
2933     calls, and wasn't printing the correct value for compiling calls. Increased the
2934     default value of LOOPREPEAT, and the number of significant figures in the
2935     times.
2937     4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
2939     5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
2940     a building problem on Windows NT with a FAT file system.
2943 nigel 25 Version 2.01 21-Oct-98
2944     ----------------------
2946     1. Changed the API for pcre_compile() to allow for the provision of a pointer
2947     to character tables built by pcre_maketables() in the current locale. If NULL
2948     is passed, the default tables are used.
2951 nigel 23 Version 2.00 24-Sep-98
2952 nigel 21 ----------------------
2954 nigel 23 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
2955     it any more.
2957     2. Allow quantification of (?>) groups, and make it work correctly.
2959     3. The first character computation wasn't working for (?>) groups.
2961     4. Correct the implementation of \Z (it is permitted to match on the \n at the
2962     end of the subject) and add 5.005's \z, which really does match only at the
2963     very end of the subject.
2965     5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
2967     6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
2968     DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
2969     localized options. All options to pcre_study() were also removed.
2971     7. Add other new features from 5.005:
2973     $(?<= positive lookbehind
2974     $(?<! negative lookbehind
2975     (?imsx-imsx) added the unsetting capability
2976     such a setting is global if at outer level; local otherwise
2977     (?imsx-imsx:) non-capturing groups with option setting
2978     (?(cond)re|re) conditional pattern matching
2980     A backreference to itself in a repeated group matches the previous
2981     captured string.
2983     8. General tidying up of studying (both automatic and via "study")
2984     consequential on the addition of new assertions.
2986     9. As in 5.005, unlimited repeated groups that could match an empty substring
2987     are no longer faulted at compile time. Instead, the loop is forcibly broken at
2988     runtime if any iteration does actually match an empty substring.
2990     10. Include the RunTest script in the distribution.
2992     11. Added tests from the Perl 5.005_02 distribution. This showed up a few
2993     discrepancies, some of which were old and were also with respect to 5.004. They
2994     have now been fixed.
2997     Version 1.09 28-Apr-98
2998     ----------------------
3000 nigel 21 1. A negated single character class followed by a quantifier with a minimum
3001     value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
3002     program crashes, or just wrong answers. This did not apply to negated classes
3003     containing more than one character, or to minima other than one.
3006 nigel 19 Version 1.08 27-Mar-98
3007     ----------------------
3009     1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
3011     2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
3012     latter must appear before anything that relies on it in the pattern.
3015 nigel 17 Version 1.07 16-Feb-98
3016     ----------------------
3018     1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
3019     repeat of a potentially empty string).
3022 nigel 15 Version 1.06 23-Jan-98
3023     ----------------------
3025     1. Added Markus Oberhumer's little patches for C++.
3027     2. Literal strings longer than 255 characters were broken.
3030 nigel 13 Version 1.05 23-Dec-97
3031     ----------------------
3033     1. Negated character classes containing more than one character were failing if
3034     PCRE_CASELESS was set at run time.
3037 nigel 11 Version 1.04 19-Dec-97
3038     ----------------------
3040     1. Corrected the man page, where some "const" qualifiers had been omitted.
3042     2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
3043     input syntax.
3045     3. Fixed memory leak which occurred when a regex with back references was
3046     matched with an offsets vector that wasn't big enough. The temporary memory
3047     that is used in this case wasn't being freed if the match failed.
3049     4. Tidied pcretest to ensure it frees memory that it gets.
3051     5. Temporary memory was being obtained in the case where the passed offsets
3052     vector was exactly big enough.
3054     6. Corrected definition of offsetof() from change 5 below.
3056     7. I had screwed up change 6 below and broken the rules for the use of
3057     setjmp(). Now fixed.
3060 nigel 9 Version 1.03 18-Dec-97
3061     ----------------------
3063     1. A erroneous regex with a missing opening parenthesis was correctly
3064     diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
3065     on some systems.
3067     2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
3068     it was reported that one broken compiler failed on the former because "code" is
3069     also an independent variable.
3071     3. The erroneous regex a[]b caused an array overrun reference.
3073     4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
3074     fail on data ending with that character. (It was going on too far, and checking
3075     the next character, typically a binary zero.) This was specific to the
3076     optimized code for single-character negative classes.
3078     5. Added a contributed patch from the TIN world which does the following:
3080     + Add an undef for memmove, in case the the system defines a macro for it.
3082     + Add a definition of offsetof(), in case there isn't one. (I don't know
3083     the reason behind this - offsetof() is part of the ANSI standard - but
3084     it does no harm).
3086     + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
3087     most of the places where whitespace preceded '#'. I have given up and
3088     allowed the remaining 2 cases to be at the margin.
3090     + Rename some variables in pcre to eliminate shadowing. This seems very
3091     pedantic, but does no harm, of course.
3093     6. Moved the call to setjmp() into its own function, to get rid of warnings
3094     from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
3096     7. Constructs such as \d{8,} were compiling into the equivalent of
3097 nigel 11 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
3098 nigel 9 outcome, but in this particular case used more store than had been allocated,
3099     which caused the bug to be discovered because it threw up an internal error.
3101     8. The debugging code in both pcre and pcretest for outputting the compiled
3102     form of a regex was going wrong in the case of back references followed by
3103     curly-bracketed repeats.
3106 nigel 7 Version 1.02 12-Dec-97
3107     ----------------------
3109     1. Typos in pcre.3 and comments in the source fixed.
3111     2. Applied a contributed patch to get rid of places where it used to remove
3112     'const' from variables, and fixed some signed/unsigned and uninitialized
3113     variable warnings.
3115     3. Added the "runtest" target to Makefile.
3117     4. Set default compiler flag to -O2 rather than just -O.
3120 nigel 5 Version 1.01 19-Nov-97
3121     ----------------------
3123     1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
3124     like /([ab]*)*/, that is, for classes with more than one character in them.
3126     2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
3127     as /((?>a*))*/ (a PCRE_EXTRA facility).
3130     Version 1.00 18-Nov-97
3131     ----------------------
3133     1. Added compile-time macros to support systems such as SunOS4 which don't have
3134     memmove() or strerror() but have other things that can be used instead.
3136     2. Arranged that "make clean" removes the executables.
3139 nigel 3 Version 0.99 27-Oct-97
3140     ----------------------
3142     1. Fixed bug in code for optimizing classes with only one character. It was
3143     initializing a 32-byte map regardless, which could cause it to run off the end
3144     of the memory it had got.
3146     2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
3149     Version 0.98 22-Oct-97
3150     ----------------------
3152     1. Fixed bug in code for handling temporary memory usage when there are more
3153     back references than supplied space in the ovector. This could cause segfaults.
3156     Version 0.97 21-Oct-97
3157     ----------------------
3159     1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
3161     2. Optimized negated single characters not to use a bit map.
3163     3. Brought error texts together as macro definitions; clarified some of them;
3164     fixed one that was wrong - it said "range out of order" when it meant "invalid
3165     escape sequence".
3167     4. Changed some char * arguments to const char *.
3169     5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
3171     6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
3172     pcretest.
3175     Version 0.96 16-Oct-97
3176     ----------------------
3178     1. Added a simple "pgrep" utility to the distribution.
3180     2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
3181     unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
3182     where "ddd" means "one or more decimal digits".
3184     3. Fixed serious bug. If a pattern had a back reference, but the call to
3185     pcre_exec() didn't supply a large enough ovector to record the related
3186     identifying subpattern, the match always failed. PCRE now remembers the number
3187     of the largest back reference, and gets some temporary memory in which to save
3188     the offsets during matching if necessary, in order to ensure that
3189     backreferences always work.
3191     4. Increased the compatibility with Perl in a number of ways:
3193     (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
3194     to request this handling. The option can be set at compile or exec time.
3196     (b) $ matches before a terminating newline by default; an option
3197     PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
3198     mode). The option can be set at compile or exec time.
3200     (c) The handling of \ followed by a digit other than 0 is now supposed to be
3201     the same as Perl's. If the decimal number it represents is less than 10
3202     or there aren't that many previous left capturing parentheses, an octal
3203     escape is read. Inside a character class, it's always an octal escape,
3204     even if it is a single digit.
3206     (d) An escaped but undefined alphabetic character is taken as a literal,
3207     unless PCRE_EXTRA is set. Currently this just reserves the remaining
3208     escapes.
3210     (e) {0} is now permitted. (The previous item is removed from the compiled
3211     pattern).
3213     5. Changed all the names of code files so that the basic parts are no longer
3214     than 10 characters, and abolished the teeny "globals.c" file.
3216     6. Changed the handling of character classes; they are now done with a 32-byte
3217     bit map always.
3219     7. Added the -d and /D options to pcretest to make it possible to look at the
3220     internals of compilation without having to recompile pcre.
3223     Version 0.95 23-Sep-97
3224     ----------------------
3226     1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
3227     \x20 at the start of a run of normal characters. These were being treated as
3228     real characters, instead of the source characters being re-checked.
3231     Version 0.94 18-Sep-97
3232     ----------------------
3234     1. The functions are now thread-safe, with the caveat that the global variables
3235     containing pointers to malloc() and free() or alternative functions are the
3236     same for all threads.
3238     2. Get pcre_study() to generate a bitmap of initial characters for non-
3239     anchored patterns when this is possible, and use it if passed to pcre_exec().
3242     Version 0.93 15-Sep-97
3243     ----------------------
3245     1. /(b)|(:+)/ was computing an incorrect first character.
3247     2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
3248     but not actually doing anything yet.
3250     3. Treat "-" characters in classes that cannot be part of ranges as literals,
3251     as Perl does (e.g. [-az] or [az-]).
3253     4. Set the anchored flag if a branch starts with .* or .*? because that tests
3254     all possible positions.
3256     5. Split up into different modules to avoid including unneeded functions in a
3257     compiled binary. However, compile and exec are still in one module. The "study"
3258     function is split off.
3260     6. The character tables are now in a separate module whose source is generated
3261     by an auxiliary program - but can then be edited by hand if required. There are
3262     now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
3263     toupper() in the code.
3265     7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
3266     make them global. Abolish the function for setting them, as the caller can now
3267     set them directly.
3270     Version 0.92 11-Sep-97
3271     ----------------------
3273     1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
3274     (e.g. /a{1,3}/) was broken (I mis-optimized it).
3276     2. Caseless matching was not working in character classes if the characters in
3277     the pattern were in upper case.
3279     3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
3281     4. Make PCRE_ANCHORED public and accept as a compile option.
3283     5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
3284     PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
3285     pass them.
3287     6. Give an error if bad option bits passed at compile or run time.
3289     7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
3290     pcretest to cause it to pass that flag.
3292     8. Add pcre_info(), to get the number of identifying subpatterns, the stored
3293     options, and the first character, if set.
3295     9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
3298     Version 0.91 10-Sep-97
3299     ----------------------
3301     1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
3302     match the empty string as in /(a*)*/. It was looping and ultimately crashing.
3304     2. PCRE was looping on encountering an indefinitely repeated back reference to
3305     a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
3306     Perl does - treats the match as successful.
3308     ****


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