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Revision 343 - (hide annotations) (download)
Mon Apr 21 16:30:37 2008 UTC (6 years, 7 months ago) by ph10
File size: 155708 byte(s)
Fixes to pcretest for readline support on Windows.

1 nigel 3 ChangeLog for PCRE
2     ------------------
3    
4 ph10 321 Version 7.7 05-Mar-08
5     ---------------------
6    
7     1. Applied Craig's patch to sort out a long long problem: "If we can't convert
8     a string to a long long, pretend we don't even have a long long." This is
9     done by checking for the strtoq, strtoll, and _strtoi64 functions.
10 ph10 322
11     2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
12     pre-7.6 versions, which defined a global no_arg variable instead of putting
13 ph10 332 it in the RE class. (See also #8 below.)
14 ph10 323
15     3. Remove a line of dead code, identified by coverity and reported by Nuno
16     Lopes.
17 ph10 324
18     4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
19 ph10 321
20 ph10 324 (1) The include/exclude patterns were being applied to the whole pathnames
21     of files, instead of just to the final components.
22    
23     (2) If there was more than one level of directory, the subdirectories were
24     skipped unless they satisfied the include/exclude conditions. This is
25     inconsistent with GNU grep (and could even be seen as contrary to the
26     pcregrep specification - which I improved to make it absolutely clear).
27     The action now is always to scan all levels of directory, and just
28     apply the include/exclude patterns to regular files.
29 ph10 325
30     5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
31     --exclude_dir in the tests to avoid scanning .svn directories.
32 ph10 326
33     6. Applied Craig's patch to the QuoteMeta function so that it escapes the
34     NUL character as backslash + 0 rather than backslash + NUL, because PCRE
35     doesn't support NULs in patterns.
36 ph10 327
37     7. Added some missing "const"s to declarations of static tables in
38     pcre_compile.c and pcre_dfa_exec.c.
39 ph10 328
40     8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
41 ph10 329 caused by fix #2 above. (Subsequently also a second patch to fix the
42 ph10 330 first patch. And a third patch - this was a messy problem.)
43 ph10 331
44     9. Applied Craig's patch to remove the use of push_back().
45 ph10 321
46 ph10 332 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
47     matching function regexec().
48 ph10 333
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     references. PCRE supports relative numbers with this syntax (I don't think
52     Oniguruma does).
53 ph10 335
54     12. Previously, a group with a zero repeat such as (...){0} was completely
55     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     (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     time.
60 ph10 336
61 ph10 341 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
62     to the way PCRE behaves:
63    
64 ph10 336 (a) A lone ] character is dis-allowed (Perl treats it as data).
65 ph10 341
66 ph10 336 (b) A back reference to an unmatched subpattern matches an empty string
67     (Perl fails the current match path).
68 ph10 340
69 ph10 341 (c) A data ] in a character class must be notated as \] because if the
70     first data character in a class is ], it defines an empty class. (In
71     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    
76 ph10 340 14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
77     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     compiled code was correct. (When scanning forwards to check for the
81     existencd of the subpattern, it was treating the data ']' as terminating
82     the class, so got the count wrong. When actually compiling, the reference
83     was subsequently set up correctly.)
84 ph10 341
85     15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
86     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).
89 ph10 342
90     16. The implementation of 13c above involved the invention of a new opcode,
91     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.
96 ph10 343
97     17. Compiling pcretest on Windows with readline support failed without the
98     following two fixes: (1) Make the unistd.h include conditional on
99     HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
100 ph10 324
101 ph10 332
102 ph10 319 Version 7.6 28-Jan-08
103 ph10 300 ---------------------
104    
105 ph10 302 1. A character class containing a very large number of characters with
106     codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
107     overflow.
108 ph10 309
109     2. Patch to cut out the "long long" test in pcrecpp_unittest when
110     HAVE_LONG_LONG is not defined.
111    
112 ph10 303 3. Applied Christian Ehrlicher's patch to update the CMake build files to
113 ph10 304 bring them up to date and include new features. This patch includes:
114 ph10 309
115 ph10 304 - Fixed PH's badly added libz and libbz2 support.
116     - Fixed a problem with static linking.
117 ph10 312 - Added pcredemo. [But later removed - see 7 below.]
118 ph10 304 - Fixed dftables problem and added an option.
119     - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
120     HAVE_LONG_LONG.
121     - Added readline support for pcretest.
122 ph10 309 - Added an listing of the option settings after cmake has run.
123    
124 ph10 314 4. A user submitted a patch to Makefile that makes it easy to create
125     "pcre.dll" under mingw when using Configure/Make. I added stuff to
126     Makefile.am that cause it to include this special target, without
127     affecting anything else. Note that the same mingw target plus all
128     the other distribution libraries and programs are now supported
129     when configuring with CMake (see 6 below) instead of with
130     Configure/Make.
131 ph10 309
132 ph10 308 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
133     This is an attempt to solve the reported problem "pcrecpp::no_arg is not
134 ph10 309 exported in the Windows port". It has not yet been confirmed that the patch
135     solves the problem, but it does no harm.
136 ph10 313
137 ph10 311 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
138 ph10 319 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
139 ph10 314 with CMake, and also correct the comment about stack recursion.
140 ph10 313
141 ph10 312 7. Remove the automatic building of pcredemo from the ./configure system and
142 ph10 313 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
143     of a program that users should build themselves after PCRE is installed, so
144     building it automatically is not really right. What is more, it gave
145 ph10 312 trouble in some build environments.
146 ph10 300
147 ph10 319 8. Further tidies to CMakeLists.txt from Sheri and Christian.
148 ph10 308
149 ph10 319
150 ph10 298 Version 7.5 10-Jan-08
151 ph10 263 ---------------------
152    
153     1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
154     values in parens when parsing an RE using the C++ wrapper."
155 ph10 286
156 ph10 264 2. Negative specials like \S did not work in character classes in UTF-8 mode.
157     Characters greater than 255 were excluded from the class instead of being
158     included.
159 ph10 286
160     3. The same bug as (2) above applied to negated POSIX classes such as
161 ph10 265 [:^space:].
162 ph10 286
163 ph10 267 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
164     defined or documented. It seems to have been a typo for PCRE_STATIC, so
165 ph10 286 I have changed it.
166    
167 ph10 268 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
168 ph10 286 first named subpattern) and a construct such as (?&a) would reference the
169     first named subpattern whose name started with "a" (in other words, the
170 ph10 272 length check was missing). Both these problems are fixed. "Subpattern name
171     expected" is now given for (?&) (a zero-length name), and this patch also
172     makes it give the same error for \k'' (previously it complained that that
173     was a reference to a non-existent subpattern).
174 ph10 286
175 ph10 269 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
176 ph10 286 this is right because (?- can be followed by option settings as well as by
177 ph10 269 digits. I have, however, made the messages clearer.
178 ph10 286
179 ph10 270 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
180     than the number used in the conditional) now cause a compile-time error.
181     This is actually not compatible with Perl, which accepts such patterns, but
182     treats the conditional as always being FALSE (as PCRE used to), but it
183     seems to me that giving a diagnostic is better.
184 ph10 286
185 ph10 274 8. Change "alphameric" to the more common word "alphanumeric" in comments
186 ph10 275 and messages.
187 ph10 286
188     9. Fix two occurrences of "backslash" in comments that should have been
189     "backspace".
190    
191     10. Remove two redundant lines of code that can never be obeyed (their function
192     was moved elsewhere).
193    
194     11. The program that makes PCRE's Unicode character property table had a bug
195     which caused it to generate incorrect table entries for sequences of
196 ph10 277 characters that have the same character type, but are in different scripts.
197 ph10 286 It amalgamated them into a single range, with the script of the first of
198 ph10 277 them. In other words, some characters were in the wrong script. There were
199     thirteen such cases, affecting characters in the following ranges:
200 ph10 286
201 ph10 277 U+002b0 - U+002c1
202     U+0060c - U+0060d
203 ph10 286 U+0061e - U+00612
204 ph10 277 U+0064b - U+0065e
205     U+0074d - U+0076d
206     U+01800 - U+01805
207     U+01d00 - U+01d77
208     U+01d9b - U+01dbf
209     U+0200b - U+0200f
210     U+030fc - U+030fe
211     U+03260 - U+0327f
212     U+0fb46 - U+0fbb1
213     U+10450 - U+1049d
214 ph10 286
215 ph10 279 12. The -o option (show only the matching part of a line) for pcregrep was not
216     compatible with GNU grep in that, if there was more than one match in a
217     line, it showed only the first of them. It now behaves in the same way as
218     GNU grep.
219 ph10 286
220     13. If the -o and -v options were combined for pcregrep, it printed a blank
221     line for every non-matching line. GNU grep prints nothing, and pcregrep now
222     does the same. The return code can be used to tell if there were any
223     non-matching lines.
224    
225 ph10 289 14. Added --file-offsets and --line-offsets to pcregrep.
226    
227     15. The pattern (?=something)(?R) was not being diagnosed as a potentially
228 ph10 282 infinitely looping recursion. The bug was that positive lookaheads were not
229 ph10 286 being skipped when checking for a possible empty match (negative lookaheads
230     and both kinds of lookbehind were skipped).
231    
232 ph10 289 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
233 ph10 284 inclusion of <windows.h> to before rather than after the definition of
234     INVALID_FILE_ATTRIBUTES (patch from David Byron).
235 ph10 263
236 ph10 289 17. Specifying a possessive quantifier with a specific limit for a Unicode
237 ph10 286 character property caused pcre_compile() to compile bad code, which led at
238     runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
239     are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
240     caused the error; without that there was no problem.
241 ph10 263
242 ph10 289 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
243 ph10 286
244 ph10 289 19. Added --enable-pcretest-libreadline.
245 ph10 286
246 ph10 289 20. In pcrecpp.cc, the variable 'count' was incremented twice in
247 ph10 288 RE::GlobalReplace(). As a result, the number of replacements returned was
248 ph10 298 double what it should be. I removed one of the increments, but Craig sent a
249     later patch that removed the other one (the right fix) and added unit tests
250     that check the return values (which was not done before).
251 ph10 292
252 ph10 291 21. Several CMake things:
253 ph10 287
254 ph10 291 (1) Arranged that, when cmake is used on Unix, the libraries end up with
255 ph10 292 the names libpcre and libpcreposix, not just pcre and pcreposix.
256 ph10 288
257 ph10 292 (2) The above change means that pcretest and pcregrep are now correctly
258     linked with the newly-built libraries, not previously installed ones.
259 ph10 291
260 ph10 292 (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
261 ph10 298
262     22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
263     crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
264     UTF-8 newline character). The key issue is that the pattern starts .*;
265     this means that the match must be either at the beginning, or after a
266     newline. The bug was in the code for advancing after a failed match and
267     checking that the new position followed a newline. It was not taking
268 ph10 294 account of UTF-8 characters correctly.
269 ph10 298
270     23. PCRE was behaving differently from Perl in the way it recognized POSIX
271     character classes. PCRE was not treating the sequence [:...:] as a
272     character class unless the ... were all letters. Perl, however, seems to
273     allow any characters between [: and :], though of course it rejects as
274     unknown any "names" that contain non-letters, because all the known class
275     names consist only of letters. Thus, Perl gives an error for [[:1234:]],
276     for example, whereas PCRE did not - it did not recognize a POSIX character
277     class. This seemed a bit dangerous, so the code has been changed to be
278     closer to Perl. The behaviour is not identical to Perl, because PCRE will
279     diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
280     treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
281     Perl does, and where it didn't before.
282    
283 ph10 296 24. Rewrite so as to remove the single use of %n from pcregrep because in some
284     Windows environments %n is disabled by default.
285 ph10 292
286    
287 ph10 260 Version 7.4 21-Sep-07
288 ph10 230 ---------------------
289    
290     1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
291 ph10 231 means that a class such as [\s] counted as "explicit reference to CR or
292     LF". That isn't really right - the whole point of the change was to try to
293     help when there was an actual mention of one of the two characters. So now
294     the change happens only if \r or \n (or a literal CR or LF) character is
295 ph10 230 encountered.
296 ph10 231
297     2. The 32-bit options word was also used for 6 internal flags, but the numbers
298     of both had grown to the point where there were only 3 bits left.
299     Fortunately, there was spare space in the data structure, and so I have
300     moved the internal flags into a new 16-bit field to free up more option
301 ph10 230 bits.
302 ph10 231
303     3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
304     but did not set the internal JCHANGED flag - either of these is enough to
305     control the way the "get" function works - but the PCRE_INFO_JCHANGED
306     facility is supposed to tell if (?J) was ever used, so now (?J) at the
307 ph10 230 start sets both bits.
308    
309 ph10 231 4. Added options (at build time, compile time, exec time) to change \R from
310     matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
311 ph10 230
312 ph10 243 5. doc/pcresyntax.html was missing from the distribution.
313    
314     6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
315 ph10 233 compatibility, even though it is no longer used.
316 ph10 243
317     7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
318 ph10 254 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
319 ph10 259 windows.h file is present (where different names are used). [This was
320 ph10 257 reversed later after testing - see 16 below.]
321 ph10 243
322     8. Changed all #include <config.h> to #include "config.h". There were also
323 ph10 236 some further <pcre.h> cases that I changed to "pcre.h".
324 ph10 243
325 ph10 239 9. When pcregrep was used with the --colour option, it missed the line ending
326 ph10 243 sequence off the lines that it output.
327    
328     10. It was pointed out to me that arrays of string pointers cause lots of
329     relocations when a shared library is dynamically loaded. A technique of
330     using a single long string with a table of offsets can drastically reduce
331     these. I have refactored PCRE in four places to do this. The result is
332 ph10 240 dramatic:
333 ph10 243
334 ph10 240 Originally: 290
335     After changing UCP table: 187
336 ph10 243 After changing error message table: 43
337 ph10 240 After changing table of "verbs" 36
338     After changing table of Posix names 22
339 ph10 243
340 ph10 240 Thanks to the folks working on Gregex for glib for this insight.
341 ph10 247
342 ph10 244 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
343 ph10 247 unicode-properties was also set.
344    
345 ph10 248 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
346 ph10 231
347 ph10 253 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
348     checked only for CRLF.
349 ph10 233
350 ph10 259 14. Added casts to pcretest.c to avoid compiler warnings.
351    
352 ph10 256 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
353 ph10 253
354 ph10 257 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
355 ph10 259 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
356     entirely. This removes changes made in 7 above.
357 ph10 256
358 ph10 261 17. The CMake files have been updated, and there is now more information about
359     building with CMake in the NON-UNIX-USE document.
360 ph10 257
361 ph10 261
362 ph10 228 Version 7.3 28-Aug-07
363 ph10 157 ---------------------
364    
365 ph10 189 1. In the rejigging of the build system that eventually resulted in 7.1, the
366     line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
367     brackets there is not right, since it causes compilers to look for an
368     installed pcre.h, not the version that is in the source that is being
369     compiled (which of course may be different). I have changed it back to:
370 ph10 197
371 ph10 189 #include "pcre.h"
372 ph10 197
373     I have a vague recollection that the change was concerned with compiling in
374     different directories, but in the new build system, that is taken care of
375     by the VPATH setting the Makefile.
376    
377 ph10 190 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
378     when the subject happened to end in the byte 0x85 (e.g. if the last
379     character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
380     characters but of course it shouldn't be taken as a newline when it is part
381     of another character. The bug was that, for an unlimited repeat of . in
382     not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
383     characters when looking for a newline.
384 ph10 197
385     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
386    
387     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
388     in debug output.
389    
390 ph10 201 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
391     long printing in the pcrecpp unittest when running under MinGW.
392 ph10 189
393 ph10 197 6. ESC_K was left out of the EBCDIC table.
394 ph10 189
395 ph10 197 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
396     parentheses; I made it 1000, which seemed large enough. Unfortunately, the
397     limit also applies to "virtual nesting" when a pattern is recursive, and in
398     this case 1000 isn't so big. I have been able to remove this limit at the
399     expense of backing off one optimization in certain circumstances. Normally,
400     when pcre_exec() would call its internal match() function recursively and
401     immediately return the result unconditionally, it uses a "tail recursion"
402     feature to save stack. However, when a subpattern that can match an empty
403     string has an unlimited repetition quantifier, it no longer makes this
404     optimization. That gives it a stack frame in which to save the data for
405     checking that an empty string has been matched. Previously this was taken
406     from the 1000-entry workspace that had been reserved. So now there is no
407     explicit limit, but more stack is used.
408 ph10 189
409 ph10 200 8. Applied Daniel's patches to solve problems with the import/export magic
410     syntax that is required for Windows, and which was going wrong for the
411     pcreposix and pcrecpp parts of the library. These were overlooked when this
412     problem was solved for the main library.
413 ph10 197
414 ph10 202 9. There were some crude static tests to avoid integer overflow when computing
415     the size of patterns that contain repeated groups with explicit upper
416     limits. As the maximum quantifier is 65535, the maximum group length was
417     set at 30,000 so that the product of these two numbers did not overflow a
418     32-bit integer. However, it turns out that people want to use groups that
419     are longer than 30,000 bytes (though not repeat them that many times).
420     Change 7.0/17 (the refactoring of the way the pattern size is computed) has
421     made it possible to implement the integer overflow checks in a much more
422     dynamic way, which I have now done. The artificial limitation on group
423     length has been removed - we now have only the limit on the total length of
424     the compiled pattern, which depends on the LINK_SIZE setting.
425 ph10 208
426     10. Fixed a bug in the documentation for get/copy named substring when
427     duplicate names are permitted. If none of the named substrings are set, the
428     functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
429     empty string.
430    
431     11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
432     instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
433     because the ] is interpreted as the first data character and the
434     terminating ] is not found. PCRE has been made compatible with Perl in this
435     regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
436     cause memory overwriting.
437    
438 ph10 206 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
439     string has been matched (to stop an infinite loop). It was not recognizing
440 ph10 208 a conditional subpattern that could match an empty string if that
441 ph10 206 subpattern was within another subpattern. For example, it looped when
442 ph10 208 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
443 ph10 206 condition was not nested. This bug has been fixed.
444 ph10 208
445 ph10 207 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
446     past the start of the subject in the presence of bytes with the top bit
447     set, for example "\x8aBCD".
448 ph10 211
449 ph10 210 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
450     (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
451 ph10 200
452 ph10 211 14. Optimized (?!) to (*FAIL).
453 ph10 202
454 ph10 212 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
455     This restricts code points to be within the range 0 to 0x10FFFF, excluding
456     the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
457     full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
458     does: it's just the validity check that is more restrictive.
459 ph10 220
460     16. Inserted checks for integer overflows during escape sequence (backslash)
461     processing, and also fixed erroneous offset values for syntax errors during
462     backslash processing.
463    
464 ph10 214 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
465 ph10 220 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
466    
467 ph10 215 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
468     caused an overrun.
469 ph10 220
470     19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
471     something other than just ASCII characters) inside a group that had an
472     unlimited repeat caused a loop at compile time (while checking to see
473     whether the group could match an empty string).
474    
475 ph10 217 20. Debugging a pattern containing \p or \P could cause a crash. For example,
476     [\P{Any}] did so. (Error in the code for printing property names.)
477 ph10 210
478 ph10 220 21. An orphan \E inside a character class could cause a crash.
479    
480     22. A repeated capturing bracket such as (A)? could cause a wild memory
481 ph10 218 reference during compilation.
482 ph10 220
483     23. There are several functions in pcre_compile() that scan along a compiled
484     expression for various reasons (e.g. to see if it's fixed length for look
485 ph10 218 behind). There were bugs in these functions when a repeated \p or \P was
486 ph10 220 present in the pattern. These operators have additional parameters compared
487     with \d, etc, and these were not being taken into account when moving along
488 ph10 218 the compiled data. Specifically:
489 ph10 220
490     (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
491     length.
492    
493     (b) An item such as \pL+ within a repeated group could cause crashes or
494 ph10 218 loops.
495 ph10 220
496 ph10 218 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
497 ph10 220 "reference to non-existent subpattern" error.
498    
499 ph10 221 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
500    
501 ph10 219 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
502 ph10 220 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
503 ph10 211
504 ph10 222 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
505 ph10 218
506 ph10 227 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
507 ph10 223 character were causing crashes (broken optimization).
508 ph10 227
509 ph10 224 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
510 ph10 227 \p or \P) caused a compile-time loop.
511    
512 ph10 226 28. More problems have arisen in unanchored patterns when CRLF is a valid line
513     break. For example, the unstudied pattern [\r\n]A does not match the string
514     "\r\nA" because change 7.0/46 below moves the current point on by two
515     characters after failing to match at the start. However, the pattern \nA
516 ph10 227 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
517     the same is true. There doesn't seem any very clean way out of this, but
518     what I have chosen to do makes the common cases work: PCRE now takes note
519     of whether there can be an explicit match for \r or \n anywhere in the
520     pattern, and if so, 7.0/46 no longer applies. As part of this change,
521     there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
522     pattern has explicit CR or LF references.
523 ph10 222
524 ph10 227 29. Added (*CR) etc for changing newline setting at start of pattern.
525 ph10 223
526 ph10 227
527 ph10 189 Version 7.2 19-Jun-07
528     ---------------------
529    
530 ph10 157 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
531     which is apparently normally available under Windows.
532 ph10 159
533     2. Re-jig the pcregrep tests with different newline settings in an attempt
534     to make them independent of the local environment's newline setting.
535 ph10 157
536 ph10 160 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
537 ph10 165
538 ph10 161 4. Some of the "internals" tests were previously cut out when the link size
539     was not 2, because the output contained actual offsets. The recent new
540 ph10 165 "Z" feature of pcretest means that these can be cut out, making the tests
541     usable with all link sizes.
542    
543 ph10 164 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
544     stack recursion. This gives a massive performance boost under BSD, but just
545 ph10 165 a small improvement under Linux. However, it saves one field in the frame
546 ph10 164 in all cases.
547 ph10 172
548 ph10 166 6. Added more features from the forthcoming Perl 5.10:
549 ph10 172
550 ph10 166 (a) (?-n) (where n is a string of digits) is a relative subroutine or
551     recursion call. It refers to the nth most recently opened parentheses.
552 ph10 172
553 ph10 166 (b) (?+n) is also a relative subroutine call; it refers to the nth next
554 ph10 172 to be opened parentheses.
555    
556     (c) Conditions that refer to capturing parentheses can be specified
557 ph10 167 relatively, for example, (?(-2)... or (?(+3)...
558 ph10 172
559 ph10 168 (d) \K resets the start of the current match so that everything before
560 ph10 172 is not part of it.
561    
562 ph10 171 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
563 ph10 172
564 ph10 171 (f) \g{name} is another synonym - part of Perl 5.10's unification of
565 ph10 172 reference syntax.
566 ph10 182
567 ph10 175 (g) (?| introduces a group in which the numbering of parentheses in each
568 ph10 182 alternative starts with the same number.
569 ph10 172
570 ph10 182 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
571    
572 ph10 172 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
573     PCRE_INFO_JCHANGED.
574    
575     8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
576     terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
577 ph10 170 for detecting groups that can match an empty string.
578 ph10 159
579 ph10 172 9. A pattern with a very large number of alternatives (more than several
580     hundred) was running out of internal workspace during the pre-compile
581     phase, where pcre_compile() figures out how much memory will be needed. A
582     bit of new cunning has reduced the workspace needed for groups with
583     alternatives. The 1000-alternative test pattern now uses 12 bytes of
584     workspace instead of running out of the 4096 that are available.
585 ph10 182
586 ph10 176 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
587 ph10 172
588 ph10 179 11. Applied patch from Google to remove an optimization that didn't quite work.
589     The report of the bug said:
590 ph10 182
591 ph10 179 pcrecpp::RE("a*").FullMatch("aaa") matches, while
592     pcrecpp::RE("a*?").FullMatch("aaa") does not, and
593 ph10 182 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
594 ph10 185
595 ph10 184 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
596 ph10 185 it matched the wrong number of bytes.
597 ph10 172
598 ph10 179
599 ph10 155 Version 7.1 24-Apr-07
600 ph10 98 ---------------------
601    
602 ph10 111 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
603 ph10 122 that is more "standard", making use of automake and other Autotools. There
604 ph10 99 is some re-arrangement of the files and adjustment of comments consequent
605     on this.
606 ph10 111
607     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
608     for recursive directory scanning broke on some systems because the files
609     are not scanned in any specific order and on different systems the order
610     was different. A call to "sort" has been inserted into RunGrepTest for the
611     approprate test as a short-term fix. In the longer term there may be an
612 ph10 100 alternative.
613 ph10 111
614 ph10 100 3. I had an email from Eric Raymond about problems translating some of PCRE's
615 ph10 111 man pages to HTML (despite the fact that I distribute HTML pages, some
616     people do their own conversions for various reasons). The problems
617     concerned the use of low-level troff macros .br and .in. I have therefore
618     removed all such uses from the man pages (some were redundant, some could
619 ph10 113 be replaced by .nf/.fi pairs). The 132html script that I use to generate
620     HTML has been updated to handle .nf/.fi and to complain if it encounters
621     .br or .in.
622 ph10 111
623 ph10 100 4. Updated comments in configure.ac that get placed in config.h.in and also
624 ph10 123 arranged for config.h to be included in the distribution, with the name
625 ph10 111 config.h.generic, for the benefit of those who have to compile without
626     Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
627    
628     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
629     Weber: (1) pcre_internal.h was missing some function renames; (2) updated
630 ph10 127 makevp.bat for the current PCRE, using the additional files
631 ph10 135 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
632 ph10 111
633     6. A Windows user reported a minor discrepancy with test 2, which turned out
634     to be caused by a trailing space on an input line that had got lost in his
635 ph10 102 copy. The trailing space was an accident, so I've just removed it.
636 ph10 111
637 ph10 104 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
638 ph10 111 that is needed.
639    
640 ph10 105 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
641     as "const" (a) because they are and (b) because it helps the PHP
642     maintainers who have recently made a script to detect big data structures
643 ph10 111 in the php code that should be moved to the .rodata section. I remembered
644     to update Builducptable as well, so it won't revert if ucptable.h is ever
645 ph10 105 re-created.
646 ph10 111
647     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
648 ph10 107 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
649 ph10 111 order to be able to cut out the UTF-8 tables in the latter when UTF-8
650     support is not required. This saves 1.5-2K of code, which is important in
651 ph10 107 some applications.
652 ph10 111
653 ph10 110 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
654 ph10 111 so as not to refer to the tables, even though these functions will never be
655     called when UTF-8 support is disabled. Otherwise there are problems with a
656     shared library.
657    
658 ph10 118 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
659    
660     (a) It was defining its arguments as char * instead of void *.
661    
662 ph10 123 (b) It was assuming that all moves were upwards in memory; this was true
663     a long time ago when I wrote it, but is no longer the case.
664    
665 ph10 118 The emulated memove() is provided for those environments that have neither
666 ph10 123 memmove() nor bcopy(). I didn't think anyone used it these days, but that
667 ph10 118 is clearly not the case, as these two bugs were recently reported.
668 ph10 123
669 ph10 111 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
670 ph10 123 and Detrail to create the HTML documentation, the .txt form of the man
671     pages, and it removes trailing spaces from listed files. It also creates
672     pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
673     case, it wraps all the #defines with #ifndefs. This script should be run
674 ph10 111 before "make dist".
675 ph10 123
676 ph10 115 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
677     with Unicode property support.
678 ph10 123
679     (a) For a maximizing quantifier, if the two different cases of the
680     character were of different lengths in their UTF-8 codings (there are
681     some cases like this - I found 11), and the matching function had to
682 ph10 115 back up over a mixture of the two cases, it incorrectly assumed they
683     were both the same length.
684 ph10 123
685     (b) When PCRE was configured to use the heap rather than the stack for
686     recursion during matching, it was not correctly preserving the data for
687     the other case of a UTF-8 character when checking ahead for a match
688     while processing a minimizing repeat. If the check also involved
689 ph10 115 matching a wide character, but failed, corruption could cause an
690     erroneous result when trying to check for a repeat of the original
691     character.
692 ph10 123
693 ph10 116 13. Some tidying changes to the testing mechanism:
694 ph10 98
695 ph10 116 (a) The RunTest script now detects the internal link size and whether there
696     is UTF-8 and UCP support by running ./pcretest -C instead of relying on
697 ph10 123 values substituted by "configure". (The RunGrepTest script already did
698     this for UTF-8.) The configure.ac script no longer substitutes the
699     relevant variables.
700    
701 ph10 116 (b) The debugging options /B and /D in pcretest show the compiled bytecode
702     with length and offset values. This means that the output is different
703     for different internal link sizes. Test 2 is skipped for link sizes
704     other than 2 because of this, bypassing the problem. Unfortunately,
705     there was also a test in test 3 (the locale tests) that used /B and
706 ph10 123 failed for link sizes other than 2. Rather than cut the whole test out,
707     I have added a new /Z option to pcretest that replaces the length and
708     offset values with spaces. This is now used to make test 3 independent
709 ph10 122 of link size. (Test 2 will be tidied up later.)
710 ph10 123
711     14. If erroroffset was passed as NULL to pcre_compile, it provoked a
712 ph10 122 segmentation fault instead of returning the appropriate error message.
713 ph10 134
714 ph10 131 15. In multiline mode when the newline sequence was set to "any", the pattern
715 ph10 134 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
716     This doesn't seem right; it now treats the CRLF combination as the line
717     ending, and so does not match in that case. It's only a pattern such as ^$
718     that would hit this one: something like ^ABC$ would have failed after \r
719     and then tried again after \r\n.
720    
721 ph10 131 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
722 ph10 134 in an attempt to make files that differ only in their line terminators
723     compare equal. This works on Linux.
724 ph10 142
725 ph10 141 17. Under certain error circumstances pcregrep might try to free random memory
726     as it exited. This is now fixed, thanks to valgrind.
727 ph10 142
728 ph10 141 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
729 ph10 142 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
730     was because its rules for how to advance for /g after matching an empty
731 ph10 143 string at the end of a line did not allow for this case. They now check for
732     it specially.
733 ph10 150
734     20. pcretest is supposed to handle patterns and data of any length, by
735     extending its buffers when necessary. It was getting this wrong when the
736 ph10 147 buffer for a data line had to be extended.
737 ph10 150
738 ph10 149 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
739 ph10 150 CRLF as a newline sequence.
740 ph10 152
741 ph10 151 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
742 ph10 152 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
743     I have nevertheless tidied it up.
744 ph10 111
745 ph10 152 23. Added some casts to kill warnings from HP-UX ia64 compiler.
746 ph10 123
747 ph10 153 24. Added a man page for pcre-config.
748 ph10 152
749 ph10 153
750 nigel 93 Version 7.0 19-Dec-06
751     ---------------------
752    
753     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
754     moving to gcc 4.1.1.
755    
756     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
757     sys/time.h, which is documented as needed for this function. It doesn't
758     seem to matter on Linux, but it showed up on some releases of OS X.
759    
760     3. It seems that there are systems where bytes whose values are greater than
761     127 match isprint() in the "C" locale. The "C" locale should be the
762     default when a C program starts up. In most systems, only ASCII printing
763     characters match isprint(). This difference caused the output from pcretest
764     to vary, making some of the tests fail. I have changed pcretest so that:
765    
766     (a) When it is outputting text in the compiled version of a pattern, bytes
767     other than 32-126 are always shown as hex escapes.
768    
769     (b) When it is outputting text that is a matched part of a subject string,
770     it does the same, unless a different locale has been set for the match
771     (using the /L modifier). In this case, it uses isprint() to decide.
772    
773     4. Fixed a major bug that caused incorrect computation of the amount of memory
774     required for a compiled pattern when options that changed within the
775     pattern affected the logic of the preliminary scan that determines the
776     length. The relevant options are -x, and -i in UTF-8 mode. The result was
777     that the computed length was too small. The symptoms of this bug were
778     either the PCRE error "internal error: code overflow" from pcre_compile(),
779     or a glibc crash with a message such as "pcretest: free(): invalid next
780     size (fast)". Examples of patterns that provoked this bug (shown in
781     pcretest format) are:
782    
783     /(?-x: )/x
784     /(?x)(?-x: \s*#\s*)/
785     /((?i)[\x{c0}])/8
786     /(?i:[\x{c0}])/8
787    
788     HOWEVER: Change 17 below makes this fix obsolete as the memory computation
789     is now done differently.
790    
791     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
792     wrapper classes; (b) implement a new function in the C++ scanner that is
793     more efficient than the old way of doing things because it avoids levels of
794     recursion in the regex matching; (c) add a paragraph to the documentation
795     for the FullMatch() function.
796    
797     6. The escape sequence \n was being treated as whatever was defined as
798     "newline". Not only was this contrary to the documentation, which states
799     that \n is character 10 (hex 0A), but it also went horribly wrong when
800     "newline" was defined as CRLF. This has been fixed.
801    
802     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
803     was being set to -1 for the "end of line" case (supposedly a value that no
804     character can have). Though this value is never used (the check for end of
805     line is "zero bytes in current character"), it caused compiler complaints.
806     I've changed it to 0xffffffff.
807    
808     8. In pcre_version.c, the version string was being built by a sequence of
809     C macros that, in the event of PCRE_PRERELEASE being defined as an empty
810     string (as it is for production releases) called a macro with an empty
811     argument. The C standard says the result of this is undefined. The gcc
812     compiler treats it as an empty string (which was what was wanted) but it is
813     reported that Visual C gives an error. The source has been hacked around to
814     avoid this problem.
815    
816     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
817     builds of pcretest, and changed the call to _setmode() to use _O_BINARY
818     instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
819     of them did).
820    
821     10. Originally, pcretest opened its input and output without "b"; then I was
822     told that "b" was needed in some environments, so it was added for release
823     5.0 to both the input and output. (It makes no difference on Unix-like
824     systems.) Later I was told that it is wrong for the input on Windows. I've
825     now abstracted the modes into two macros, to make it easier to fiddle with
826     them, and removed "b" from the input mode under Windows.
827    
828     11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
829    
830     12. Added -help and --help to pcretest as an official way of being reminded
831     of the options.
832    
833     13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
834     and pcrecpp.cc because they annoy compilers at high warning levels.
835    
836     14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
837    
838     15. Fixed an occurrence of == in configure.ac that should have been = (shell
839     scripts are not C programs :-) and which was not noticed because it works
840     on Linux.
841    
842     16. pcretest is supposed to handle any length of pattern and data line (as one
843     line or as a continued sequence of lines) by extending its input buffer if
844     necessary. This feature was broken for very long pattern lines, leading to
845     a string of junk being passed to pcre_compile() if the pattern was longer
846     than about 50K.
847    
848     17. I have done a major re-factoring of the way pcre_compile() computes the
849     amount of memory needed for a compiled pattern. Previously, there was code
850     that made a preliminary scan of the pattern in order to do this. That was
851     OK when PCRE was new, but as the facilities have expanded, it has become
852     harder and harder to keep it in step with the real compile phase, and there
853     have been a number of bugs (see for example, 4 above). I have now found a
854     cunning way of running the real compile function in a "fake" mode that
855     enables it to compute how much memory it would need, while actually only
856     ever using a few hundred bytes of working memory and without too many
857     tests of the mode. This should make future maintenance and development
858     easier. A side effect of this work is that the limit of 200 on the nesting
859     depth of parentheses has been removed (though this was never a serious
860     limitation, I suspect). However, there is a downside: pcre_compile() now
861     runs more slowly than before (30% or more, depending on the pattern). I
862     hope this isn't a big issue. There is no effect on runtime performance.
863    
864     18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
865     newline (only possible for the last line of a file) and it was a
866     pattern that set a locale (followed by /Lsomething), pcretest crashed.
867    
868     19. Added additional timing features to pcretest. (1) The -tm option now times
869     matching only, not compiling. (2) Both -t and -tm can be followed, as a
870     separate command line item, by a number that specifies the number of
871     repeats to use when timing. The default is 50000; this gives better
872     precision, but takes uncomfortably long for very large patterns.
873    
874     20. Extended pcre_study() to be more clever in cases where a branch of a
875     subpattern has no definite first character. For example, (a*|b*)[cd] would
876     previously give no result from pcre_study(). Now it recognizes that the
877     first character must be a, b, c, or d.
878    
879     21. There was an incorrect error "recursive call could loop indefinitely" if
880     a subpattern (or the entire pattern) that was being tested for matching an
881     empty string contained only one non-empty item after a nested subpattern.
882     For example, the pattern (?>\x{100}*)\d(?R) provoked this error
883     incorrectly, because the \d was being skipped in the check.
884    
885     22. The pcretest program now has a new pattern option /B and a command line
886     option -b, which is equivalent to adding /B to every pattern. This causes
887     it to show the compiled bytecode, without the additional information that
888     -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
889     is the same as /B/I).
890    
891     23. A new optimization is now able automatically to treat some sequences such
892     as a*b as a*+b. More specifically, if something simple (such as a character
893     or a simple class like \d) has an unlimited quantifier, and is followed by
894     something that cannot possibly match the quantified thing, the quantifier
895     is automatically "possessified".
896    
897     24. A recursive reference to a subpattern whose number was greater than 39
898     went wrong under certain circumstances in UTF-8 mode. This bug could also
899     have affected the operation of pcre_study().
900    
901     25. Realized that a little bit of performance could be had by replacing
902     (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
903    
904     26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
905    
906     27. Possessive quantifiers such as a++ were previously implemented by turning
907     them into atomic groups such as ($>a+). Now they have their own opcodes,
908     which improves performance. This includes the automatically created ones
909     from 23 above.
910    
911     28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
912     lookahead was broken if it was not anchored. PCRE was mistakenly expecting
913     the first matched character to be a colon. This applied both to named and
914     numbered groups.
915    
916     29. The ucpinternal.h header file was missing its idempotency #ifdef.
917    
918     30. I was sent a "project" file called libpcre.a.dev which I understand makes
919     building PCRE on Windows easier, so I have included it in the distribution.
920    
921     31. There is now a check in pcretest against a ridiculously large number being
922     returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
923     loop, the loop is abandoned.
924    
925     32. Forward references to subpatterns in conditions such as (?(2)...) where
926     subpattern 2 is defined later cause pcre_compile() to search forwards in
927     the pattern for the relevant set of parentheses. This search went wrong
928     when there were unescaped parentheses in a character class, parentheses
929     escaped with \Q...\E, or parentheses in a #-comment in /x mode.
930    
931     33. "Subroutine" calls and backreferences were previously restricted to
932     referencing subpatterns earlier in the regex. This restriction has now
933     been removed.
934    
935     34. Added a number of extra features that are going to be in Perl 5.10. On the
936     whole, these are just syntactic alternatives for features that PCRE had
937     previously implemented using the Python syntax or my own invention. The
938     other formats are all retained for compatibility.
939    
940     (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
941     as (?P<name>...). The new forms, as well as being in Perl 5.10, are
942     also .NET compatible.
943    
944     (b) A recursion or subroutine call to a named group can now be defined as
945     (?&name) as well as (?P>name).
946    
947     (c) A backreference to a named group can now be defined as \k<name> or
948     \k'name' as well as (?P=name). The new forms, as well as being in Perl
949     5.10, are also .NET compatible.
950    
951     (d) A conditional reference to a named group can now use the syntax
952     (?(<name>) or (?('name') as well as (?(name).
953    
954     (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
955     groups (named and numbered) that are never evaluated inline, but can be
956     called as "subroutines" from elsewhere. In effect, the DEFINE condition
957     is always false. There may be only one alternative in such a group.
958    
959     (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
960     as the simple (?(R). The condition is true only if the most recent
961     recursion is that of the given number or name. It does not search out
962     through the entire recursion stack.
963    
964     (g) The escape \gN or \g{N} has been added, where N is a positive or
965     negative number, specifying an absolute or relative reference.
966    
967     35. Tidied to get rid of some further signed/unsigned compiler warnings and
968     some "unreachable code" warnings.
969    
970     36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
971     things, this adds five new scripts.
972    
973     37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
974     There were also incompatibilities regarding the handling of \Q..\E inside
975     character classes, for example with patterns like [\Qa\E-\Qz\E] where the
976     hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
977    
978     38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
979     matches an empty string, and forcibly breaks the loop. There were bugs in
980     this code in non-simple cases. For a pattern such as ^(a()*)* matched
981     against aaaa the result was just "a" rather than "aaaa", for example. Two
982     separate and independent bugs (that affected different cases) have been
983     fixed.
984    
985     39. Refactored the code to abolish the use of different opcodes for small
986     capturing bracket numbers. This is a tidy that I avoided doing when I
987     removed the limit on the number of capturing brackets for 3.5 back in 2001.
988     The new approach is not only tidier, it makes it possible to reduce the
989     memory needed to fix the previous bug (38).
990    
991     40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
992     sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
993     processing dot, circumflex, or dollar metacharacters, or #-comments in /x
994     mode.
995    
996     41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
997     report.
998    
999     42. Applied patch, originally from Ari Pollak, modified by Google, to allow
1000     copy construction and assignment in the C++ wrapper.
1001    
1002     43. Updated pcregrep to support "--newline=any". In the process, I fixed a
1003     couple of bugs that could have given wrong results in the "--newline=crlf"
1004     case.
1005    
1006     44. Added a number of casts and did some reorganization of signed/unsigned int
1007     variables following suggestions from Dair Grant. Also renamed the variable
1008     "this" as "item" because it is a C++ keyword.
1009    
1010     45. Arranged for dftables to add
1011    
1012     #include "pcre_internal.h"
1013    
1014     to pcre_chartables.c because without it, gcc 4.x may remove the array
1015     definition from the final binary if PCRE is built into a static library and
1016     dead code stripping is activated.
1017    
1018     46. For an unanchored pattern, if a match attempt fails at the start of a
1019     newline sequence, and the newline setting is CRLF or ANY, and the next two
1020     characters are CRLF, advance by two characters instead of one.
1021    
1022    
1023 nigel 91 Version 6.7 04-Jul-06
1024     ---------------------
1025    
1026     1. In order to handle tests when input lines are enormously long, pcretest has
1027     been re-factored so that it automatically extends its buffers when
1028     necessary. The code is crude, but this _is_ just a test program. The
1029     default size has been increased from 32K to 50K.
1030    
1031     2. The code in pcre_study() was using the value of the re argument before
1032     testing it for NULL. (Of course, in any sensible call of the function, it
1033     won't be NULL.)
1034    
1035     3. The memmove() emulation function in pcre_internal.h, which is used on
1036     systems that lack both memmove() and bcopy() - that is, hardly ever -
1037     was missing a "static" storage class specifier.
1038    
1039     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
1040     containing an extended class (one that cannot be represented by a bitmap
1041     because it contains high-valued characters or Unicode property items, e.g.
1042     [\pZ]). Almost always one would set UTF-8 mode when processing such a
1043     pattern, but PCRE should not loop if you do not (it no longer does).
1044     [Detail: two cases were found: (a) a repeated subpattern containing an
1045     extended class; (b) a recursive reference to a subpattern that followed a
1046     previous extended class. It wasn't skipping over the extended class
1047     correctly when UTF-8 mode was not set.]
1048    
1049     5. A negated single-character class was not being recognized as fixed-length
1050     in lookbehind assertions such as (?<=[^f]), leading to an incorrect
1051     compile error "lookbehind assertion is not fixed length".
1052    
1053     6. The RunPerlTest auxiliary script was showing an unexpected difference
1054     between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
1055     write a Perl script that can interpret lines of an input file either as
1056     byte characters or as UTF-8, which is what "perltest" was being required to
1057     do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
1058     can't do is switch easily at run time between having the "use utf8;" pragma
1059     or not. In the end, I fudged it by using the RunPerlTest script to insert
1060     "use utf8;" explicitly for the UTF-8 tests.
1061    
1062     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
1063     the end of the subject string, contrary to the documentation and to what
1064     Perl does. This was true of both matching functions. Now it matches only at
1065     the start of the subject and immediately after *internal* newlines.
1066    
1067     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
1068     a pointer to an int instead of a pointer to an unsigned long int. This
1069     caused problems on 64-bit systems.
1070    
1071     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
1072     instance of the 'standard' template library not being so standard".
1073    
1074     10. There was no check on the number of named subpatterns nor the maximum
1075     length of a subpattern name. The product of these values is used to compute
1076     the size of the memory block for a compiled pattern. By supplying a very
1077     long subpattern name and a large number of named subpatterns, the size
1078     computation could be caused to overflow. This is now prevented by limiting
1079     the length of names to 32 characters, and the number of named subpatterns
1080     to 10,000.
1081    
1082     11. Subpatterns that are repeated with specific counts have to be replicated in
1083     the compiled pattern. The size of memory for this was computed from the
1084     length of the subpattern and the repeat count. The latter is limited to
1085     65535, but there was no limit on the former, meaning that integer overflow
1086     could in principle occur. The compiled length of a repeated subpattern is
1087     now limited to 30,000 bytes in order to prevent this.
1088    
1089     12. Added the optional facility to have named substrings with the same name.
1090    
1091     13. Added the ability to use a named substring as a condition, using the
1092     Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
1093     are numbers (not recommended). Forward references are permitted.
1094    
1095     14. Added forward references in named backreferences (if you see what I mean).
1096    
1097     15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
1098     pattern could run off the end of the subject. For example, the pattern
1099     "(?s)(.{1,5})"8 did this with the subject "ab".
1100    
1101     16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
1102     PCRE_CASELESS was set when matching characters that were quantified with ?
1103     or *.
1104    
1105     17. A character class other than a single negated character that had a minimum
1106     but no maximum quantifier - for example [ab]{6,} - was not handled
1107     correctly by pce_dfa_exec(). It would match only one character.
1108    
1109     18. A valid (though odd) pattern that looked like a POSIX character
1110     class but used an invalid character after [ (for example [[,abc,]]) caused
1111     pcre_compile() to give the error "Failed: internal error: code overflow" or
1112     in some cases to crash with a glibc free() error. This could even happen if
1113     the pattern terminated after [[ but there just happened to be a sequence of
1114     letters, a binary zero, and a closing ] in the memory that followed.
1115    
1116     19. Perl's treatment of octal escapes in the range \400 to \777 has changed
1117     over the years. Originally (before any Unicode support), just the bottom 8
1118     bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1119     output from "man perlunicode" includes this:
1120    
1121     The regular expression compiler produces polymorphic opcodes. That
1122     is, the pattern adapts to the data and automatically switches to
1123     the Unicode character scheme when presented with Unicode data--or
1124     instead uses a traditional byte scheme when presented with byte
1125     data.
1126    
1127     Sadly, a wide octal escape does not cause a switch, and in a string with
1128     no other multibyte characters, these octal escapes are treated as before.
1129     Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
1130     /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1131     Unicode string.
1132    
1133     I have not perpetrated such confusion in PCRE. Up till now, it took just
1134     the bottom 8 bits, as in old Perl. I have now made octal escapes with
1135     values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1136     translate to the appropriate multibyte character.
1137    
1138     29. Applied some refactoring to reduce the number of warnings from Microsoft
1139     and Borland compilers. This has included removing the fudge introduced
1140     seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1141     a warning about an unused variable.
1142    
1143     21. PCRE has not included VT (character 0x0b) in the set of whitespace
1144     characters since release 4.0, because Perl (from release 5.004) does not.
1145     [Or at least, is documented not to: some releases seem to be in conflict
1146     with the documentation.] However, when a pattern was studied with
1147     pcre_study() and all its branches started with \s, PCRE still included VT
1148     as a possible starting character. Of course, this did no harm; it just
1149     caused an unnecessary match attempt.
1150    
1151     22. Removed a now-redundant internal flag bit that recorded the fact that case
1152     dependency changed within the pattern. This was once needed for "required
1153     byte" processing, but is no longer used. This recovers a now-scarce options
1154     bit. Also moved the least significant internal flag bit to the most-
1155     significant bit of the word, which was not previously used (hangover from
1156     the days when it was an int rather than a uint) to free up another bit for
1157     the future.
1158    
1159     23. Added support for CRLF line endings as well as CR and LF. As well as the
1160     default being selectable at build time, it can now be changed at runtime
1161     via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1162     specify that it is scanning data with non-default line endings.
1163    
1164     24. Changed the definition of CXXLINK to make it agree with the definition of
1165     LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1166    
1167     25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1168     recursions. This makes a big different to stack usage for some patterns.
1169    
1170     26. If a subpattern containing a named recursion or subroutine reference such
1171     as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1172     the space required for the compiled pattern went wrong and gave too small a
1173     value. Depending on the environment, this could lead to "Failed: internal
1174     error: code overflow at offset 49" or "glibc detected double free or
1175     corruption" errors.
1176    
1177     27. Applied patches from Google (a) to support the new newline modes and (b) to
1178     advance over multibyte UTF-8 characters in GlobalReplace.
1179    
1180     28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1181     difference for some implementation of PCRE in some Windows version.
1182    
1183     29. Added some extra testing facilities to pcretest:
1184    
1185     \q<number> in a data line sets the "match limit" value
1186     \Q<number> in a data line sets the "match recursion limt" value
1187     -S <number> sets the stack size, where <number> is in megabytes
1188    
1189     The -S option isn't available for Windows.
1190    
1191    
1192 nigel 89 Version 6.6 06-Feb-06
1193     ---------------------
1194    
1195     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1196     in pcreposix.h. I have copied the definition from pcre.h.
1197    
1198     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1199     because pcre.h is no longer a built file.
1200    
1201     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1202     not normally included in the compiled code.
1203    
1204    
1205 nigel 87 Version 6.5 01-Feb-06
1206     ---------------------
1207    
1208     1. When using the partial match feature with pcre_dfa_exec(), it was not
1209     anchoring the second and subsequent partial matches at the new starting
1210     point. This could lead to incorrect results. For example, with the pattern
1211     /1234/, partially matching against "123" and then "a4" gave a match.
1212    
1213     2. Changes to pcregrep:
1214    
1215     (a) All non-match returns from pcre_exec() were being treated as failures
1216     to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
1217     error message is output. Some extra information is given for the
1218     PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
1219     probably the only errors that are likely to be caused by users (by
1220     specifying a regex that has nested indefinite repeats, for instance).
1221     If there are more than 20 of these errors, pcregrep is abandoned.
1222    
1223     (b) A binary zero was treated as data while matching, but terminated the
1224     output line if it was written out. This has been fixed: binary zeroes
1225     are now no different to any other data bytes.
1226    
1227     (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
1228     used to set a locale for matching. The --locale=xxxx long option has
1229     been added (no short equivalent) to specify a locale explicitly on the
1230     pcregrep command, overriding the environment variables.
1231    
1232     (d) When -B was used with -n, some line numbers in the output were one less
1233     than they should have been.
1234    
1235     (e) Added the -o (--only-matching) option.
1236    
1237     (f) If -A or -C was used with -c (count only), some lines of context were
1238     accidentally printed for the final match.
1239    
1240     (g) Added the -H (--with-filename) option.
1241    
1242     (h) The combination of options -rh failed to suppress file names for files
1243     that were found from directory arguments.
1244    
1245     (i) Added the -D (--devices) and -d (--directories) options.
1246    
1247     (j) Added the -F (--fixed-strings) option.
1248    
1249     (k) Allow "-" to be used as a file name for -f as well as for a data file.
1250    
1251     (l) Added the --colo(u)r option.
1252    
1253     (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
1254     is not present by default.
1255    
1256     3. A nasty bug was discovered in the handling of recursive patterns, that is,
1257     items such as (?R) or (?1), when the recursion could match a number of
1258     alternatives. If it matched one of the alternatives, but subsequently,
1259     outside the recursion, there was a failure, the code tried to back up into
1260     the recursion. However, because of the way PCRE is implemented, this is not
1261     possible, and the result was an incorrect result from the match.
1262    
1263     In order to prevent this happening, the specification of recursion has
1264     been changed so that all such subpatterns are automatically treated as
1265     atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
1266    
1267     4. I had overlooked the fact that, in some locales, there are characters for
1268     which isalpha() is true but neither isupper() nor islower() are true. In
1269     the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
1270     and ordfeminine) are like this. This affected the treatment of \w and \W
1271     when they appeared in character classes, but not when they appeared outside
1272     a character class. The bit map for "word" characters is now created
1273     separately from the results of isalnum() instead of just taking it from the
1274     upper, lower, and digit maps. (Plus the underscore character, of course.)
1275    
1276     5. The above bug also affected the handling of POSIX character classes such as
1277     [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
1278     permanent tables. Instead, the bit maps for such a class were previously
1279     created as the appropriate unions of the upper, lower, and digit bitmaps.
1280     Now they are created by subtraction from the [[:word:]] class, which has
1281     its own bitmap.
1282    
1283     6. The [[:blank:]] character class matches horizontal, but not vertical space.
1284     It is created by subtracting the vertical space characters (\x09, \x0a,
1285     \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
1286     subtraction was done in the overall bitmap for a character class, meaning
1287     that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
1288     be recognized. This bug has been fixed.
1289    
1290     7. Patches from the folks at Google:
1291    
1292     (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
1293     real life, but is still worth protecting against".
1294    
1295     (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
1296     regular expressions".
1297    
1298     (c) pcre_scanner.cc: avoid use of std::count() because not all systems
1299     have it.
1300    
1301     (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
1302     "configure" and the latter not, in order to fix a problem somebody had
1303     with compiling the Arg class on HP-UX.
1304    
1305     (e) Improve the error-handling of the C++ wrapper a little bit.
1306    
1307     (f) New tests for checking recursion limiting.
1308    
1309     8. The pcre_memmove() function, which is used only if the environment does not
1310     have a standard memmove() function (and is therefore rarely compiled),
1311     contained two bugs: (a) use of int instead of size_t, and (b) it was not
1312     returning a result (though PCRE never actually uses the result).
1313    
1314     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
1315     large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
1316     returned instead of calling malloc() with an overflowing number that would
1317     most likely cause subsequent chaos.
1318    
1319     10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
1320    
1321     11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
1322     with this option is matched, the nmatch and pmatch options of regexec() are
1323     ignored.
1324    
1325     12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
1326     provided in case anyone wants to the the POSIX interface with UTF-8
1327     strings.
1328    
1329     13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
1330     C++ linking (needed for some HP-UX environments).
1331    
1332     14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
1333     (unused parameter) and in the pcre_printint() function (omitted "default"
1334     switch label when the default is to do nothing).
1335    
1336     15. Added some code to make it possible, when PCRE is compiled as a C++
1337     library, to replace subject pointers for pcre_exec() with a smart pointer
1338     class, thus making it possible to process discontinuous strings.
1339    
1340     16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
1341     much the same function. They were added by different people who were trying
1342     to make PCRE easy to compile on non-Unix systems. It has been suggested
1343     that PCRE_EXPORT be abolished now that there is more automatic apparatus
1344     for compiling on Windows systems. I have therefore replaced it with
1345     PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
1346     defaults to "extern" for C or "extern C" for C++, which works fine on
1347     Unix-like systems. It is now possible to override the value of PCRE_DATA_
1348     SCOPE with something explicit in config.h. In addition:
1349    
1350     (a) pcreposix.h still had just "extern" instead of either of these macros;
1351     I have replaced it with PCRE_DATA_SCOPE.
1352    
1353     (b) Functions such as _pcre_xclass(), which are internal to the library,
1354     but external in the C sense, all had PCRE_EXPORT in their definitions.
1355     This is apparently wrong for the Windows case, so I have removed it.
1356     (It makes no difference on Unix-like systems.)
1357    
1358     17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
1359     of recursive calls to match(). This is different to MATCH_LIMIT because
1360     that limits the total number of calls to match(), not all of which increase
1361     the depth of recursion. Limiting the recursion depth limits the amount of
1362     stack (or heap if NO_RECURSE is set) that is used. The default can be set
1363     when PCRE is compiled, and changed at run time. A patch from Google adds
1364     this functionality to the C++ interface.
1365    
1366     18. Changes to the handling of Unicode character properties:
1367    
1368     (a) Updated the table to Unicode 4.1.0.
1369    
1370     (b) Recognize characters that are not in the table as "Cn" (undefined).
1371    
1372     (c) I revised the way the table is implemented to a much improved format
1373     which includes recognition of ranges. It now supports the ranges that
1374     are defined in UnicodeData.txt, and it also amalgamates other
1375     characters into ranges. This has reduced the number of entries in the
1376     table from around 16,000 to around 3,000, thus reducing its size
1377     considerably. I realized I did not need to use a tree structure after
1378     all - a binary chop search is just as efficient. Having reduced the
1379     number of entries, I extended their size from 6 bytes to 8 bytes to
1380     allow for more data.
1381    
1382     (d) Added support for Unicode script names via properties such as \p{Han}.
1383    
1384     19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
1385     matching that character.
1386    
1387     20. When matching a repeated Unicode property with a minimum greater than zero,
1388     (for example \pL{2,}), PCRE could look past the end of the subject if it
1389     reached it while seeking the minimum number of characters. This could
1390     happen only if some of the characters were more than one byte long, because
1391     there is a check for at least the minimum number of bytes.
1392    
1393     21. Refactored the implementation of \p and \P so as to be more general, to
1394     allow for more different types of property in future. This has changed the
1395     compiled form incompatibly. Anybody with saved compiled patterns that use
1396     \p or \P will have to recompile them.
1397    
1398     22. Added "Any" and "L&" to the supported property types.
1399    
1400     23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
1401     but give a compile time error if the value is greater than 0xff.
1402    
1403     24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
1404     accidentally not being installed or uninstalled.
1405    
1406     25. The pcre.h file was built from pcre.h.in, but the only changes that were
1407     made were to insert the current release number. This seemed silly, because
1408     it made things harder for people building PCRE on systems that don't run
1409     "configure". I have turned pcre.h into a distributed file, no longer built
1410     by "configure", with the version identification directly included. There is
1411     no longer a pcre.h.in file.
1412    
1413     However, this change necessitated a change to the pcre-config script as
1414     well. It is built from pcre-config.in, and one of the substitutions was the
1415     release number. I have updated configure.ac so that ./configure now finds
1416     the release number by grepping pcre.h.
1417    
1418     26. Added the ability to run the tests under valgrind.
1419    
1420    
1421 nigel 85 Version 6.4 05-Sep-05
1422     ---------------------
1423    
1424     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
1425     "--" to be printed when multiple files were scanned, even when none of the
1426     -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
1427     consider it to be a bug, and have restored the previous behaviour.
1428    
1429     2. A couple of code tidies to get rid of compiler warnings.
1430    
1431     3. The pcretest program used to cheat by referring to symbols in the library
1432     whose names begin with _pcre_. These are internal symbols that are not
1433     really supposed to be visible externally, and in some environments it is
1434     possible to suppress them. The cheating is now confined to including
1435     certain files from the library's source, which is a bit cleaner.
1436    
1437     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
1438     file's purpose clearer.
1439    
1440     5. Reorganized pcre_ucp_findchar().
1441    
1442    
1443 nigel 83 Version 6.3 15-Aug-05
1444     ---------------------
1445    
1446     1. The file libpcre.pc.in did not have general read permission in the tarball.
1447    
1448     2. There were some problems when building without C++ support:
1449    
1450     (a) If C++ support was not built, "make install" and "make test" still
1451     tried to test it.
1452    
1453     (b) There were problems when the value of CXX was explicitly set. Some
1454     changes have been made to try to fix these, and ...
1455    
1456     (c) --disable-cpp can now be used to explicitly disable C++ support.
1457    
1458     (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
1459     backslash in a target when C++ was disabled. This confuses some
1460     versions of "make", apparently. Using an intermediate variable solves
1461     this. (Same for CPP_LOBJ.)
1462    
1463     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
1464     (non-Windows) now includes $(CFLAGS) because these flags are sometimes
1465     necessary on certain architectures.
1466    
1467     4. Added a setting of -export-symbols-regex to the link command to remove
1468     those symbols that are exported in the C sense, but actually are local
1469     within the library, and not documented. Their names all begin with
1470     "_pcre_". This is not a perfect job, because (a) we have to except some
1471     symbols that pcretest ("illegally") uses, and (b) the facility isn't always
1472     available (and never for static libraries). I have made a note to try to
1473     find a way round (a) in the future.
1474    
1475    
1476 nigel 81 Version 6.2 01-Aug-05
1477     ---------------------
1478    
1479     1. There was no test for integer overflow of quantifier values. A construction
1480     such as {1111111111111111} would give undefined results. What is worse, if
1481     a minimum quantifier for a parenthesized subpattern overflowed and became
1482     negative, the calculation of the memory size went wrong. This could have
1483     led to memory overwriting.
1484    
1485     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
1486    
1487     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
1488     operating environments where this matters.
1489    
1490     4. Applied Giuseppe Maxia's patch to add additional features for controlling
1491     PCRE options from within the C++ wrapper.
1492    
1493     5. Named capturing subpatterns were not being correctly counted when a pattern
1494     was compiled. This caused two problems: (a) If there were more than 100
1495     such subpatterns, the calculation of the memory needed for the whole
1496     compiled pattern went wrong, leading to an overflow error. (b) Numerical
1497     back references of the form \12, where the number was greater than 9, were
1498     not recognized as back references, even though there were sufficient
1499     previous subpatterns.
1500    
1501     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
1502     versions of gcc, e.g. 2.95.4.
1503    
1504    
1505 nigel 79 Version 6.1 21-Jun-05
1506     ---------------------
1507    
1508     1. There was one reference to the variable "posix" in pcretest.c that was not
1509     surrounded by "#if !defined NOPOSIX".
1510    
1511     2. Make it possible to compile pcretest without DFA support, UTF8 support, or
1512     the cross-check on the old pcre_info() function, for the benefit of the
1513     cut-down version of PCRE that is currently imported into Exim.
1514    
1515     3. A (silly) pattern starting with (?i)(?-i) caused an internal space
1516     allocation error. I've done the easy fix, which wastes 2 bytes for sensible
1517     patterns that start (?i) but I don't think that matters. The use of (?i) is
1518     just an example; this all applies to the other options as well.
1519    
1520     4. Since libtool seems to echo the compile commands it is issuing, the output
1521     from "make" can be reduced a bit by putting "@" in front of each libtool
1522     compile command.
1523    
1524     5. Patch from the folks at Google for configure.in to be a bit more thorough
1525     in checking for a suitable C++ installation before trying to compile the
1526     C++ stuff. This should fix a reported problem when a compiler was present,
1527     but no suitable headers.
1528    
1529     6. The man pages all had just "PCRE" as their title. I have changed them to
1530     be the relevant file name. I have also arranged that these names are
1531     retained in the file doc/pcre.txt, which is a concatenation in text format
1532     of all the man pages except the little individual ones for each function.
1533    
1534     7. The NON-UNIX-USE file had not been updated for the different set of source
1535     files that come with release 6. I also added a few comments about the C++
1536     wrapper.
1537    
1538    
1539 nigel 77 Version 6.0 07-Jun-05
1540     ---------------------
1541    
1542     1. Some minor internal re-organization to help with my DFA experiments.
1543    
1544     2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
1545     didn't matter for the library itself when fully configured, but did matter
1546     when compiling without UCP support, or within Exim, where the ucp files are
1547     not imported.
1548    
1549     3. Refactoring of the library code to split up the various functions into
1550     different source modules. The addition of the new DFA matching code (see
1551     below) to a single monolithic source would have made it really too
1552     unwieldy, quite apart from causing all the code to be include in a
1553     statically linked application, when only some functions are used. This is
1554     relevant even without the DFA addition now that patterns can be compiled in
1555     one application and matched in another.
1556    
1557     The downside of splitting up is that there have to be some external
1558     functions and data tables that are used internally in different modules of
1559     the library but which are not part of the API. These have all had their
1560     names changed to start with "_pcre_" so that they are unlikely to clash
1561     with other external names.
1562    
1563     4. Added an alternate matching function, pcre_dfa_exec(), which matches using
1564     a different (DFA) algorithm. Although it is slower than the original
1565     function, it does have some advantages for certain types of matching
1566     problem.
1567    
1568     5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
1569     including restarting after a partial match.
1570    
1571     6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
1572     defined when compiling for Windows was sent to me. I have put it into the
1573     code, though I have no means of testing or verifying it.
1574    
1575     7. Added the pcre_refcount() auxiliary function.
1576    
1577     8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
1578     match before or at the first newline in the subject string. In pcretest,
1579     the /f option on a pattern can be used to set this.
1580    
1581     9. A repeated \w when used in UTF-8 mode with characters greater than 256
1582     would behave wrongly. This has been present in PCRE since release 4.0.
1583    
1584     10. A number of changes to the pcregrep command:
1585    
1586     (a) Refactored how -x works; insert ^(...)$ instead of setting
1587     PCRE_ANCHORED and checking the length, in preparation for adding
1588     something similar for -w.
1589    
1590     (b) Added the -w (match as a word) option.
1591    
1592     (c) Refactored the way lines are read and buffered so as to have more
1593     than one at a time available.
1594    
1595     (d) Implemented a pcregrep test script.
1596    
1597     (e) Added the -M (multiline match) option. This allows patterns to match
1598     over several lines of the subject. The buffering ensures that at least
1599     8K, or the rest of the document (whichever is the shorter) is available
1600     for matching (and similarly the previous 8K for lookbehind assertions).
1601    
1602     (f) Changed the --help output so that it now says
1603    
1604     -w, --word-regex(p)
1605    
1606     instead of two lines, one with "regex" and the other with "regexp"
1607     because that confused at least one person since the short forms are the
1608     same. (This required a bit of code, as the output is generated
1609     automatically from a table. It wasn't just a text change.)
1610    
1611     (g) -- can be used to terminate pcregrep options if the next thing isn't an
1612     option but starts with a hyphen. Could be a pattern or a path name
1613     starting with a hyphen, for instance.
1614    
1615     (h) "-" can be given as a file name to represent stdin.
1616    
1617     (i) When file names are being printed, "(standard input)" is used for
1618     the standard input, for compatibility with GNU grep. Previously
1619     "<stdin>" was used.
1620    
1621     (j) The option --label=xxx can be used to supply a name to be used for
1622     stdin when file names are being printed. There is no short form.
1623    
1624     (k) Re-factored the options decoding logic because we are going to add
1625     two more options that take data. Such options can now be given in four
1626     different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
1627    
1628     (l) Added the -A, -B, and -C options for requesting that lines of context
1629     around matches be printed.
1630    
1631     (m) Added the -L option to print the names of files that do not contain
1632     any matching lines, that is, the complement of -l.
1633    
1634     (n) The return code is 2 if any file cannot be opened, but pcregrep does
1635     continue to scan other files.
1636    
1637     (o) The -s option was incorrectly implemented. For compatibility with other
1638     greps, it now suppresses the error message for a non-existent or non-
1639     accessible file (but not the return code). There is a new option called
1640     -q that suppresses the output of matching lines, which was what -s was
1641     previously doing.
1642    
1643     (p) Added --include and --exclude options to specify files for inclusion
1644     and exclusion when recursing.
1645    
1646     11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
1647     Hopefully, it now does.
1648    
1649     12. Missing cast in pcre_study().
1650    
1651     13. Added an "uninstall" target to the makefile.
1652    
1653     14. Replaced "extern" in the function prototypes in Makefile.in with
1654     "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
1655     world, but is set differently for Windows.
1656    
1657     15. Added a second compiling function called pcre_compile2(). The only
1658     difference is that it has an extra argument, which is a pointer to an
1659     integer error code. When there is a compile-time failure, this is set
1660     non-zero, in addition to the error test pointer being set to point to an
1661     error message. The new argument may be NULL if no error number is required
1662     (but then you may as well call pcre_compile(), which is now just a
1663     wrapper). This facility is provided because some applications need a
1664     numeric error indication, but it has also enabled me to tidy up the way
1665     compile-time errors are handled in the POSIX wrapper.
1666    
1667     16. Added VPATH=.libs to the makefile; this should help when building with one
1668     prefix path and installing with another. (Or so I'm told by someone who
1669     knows more about this stuff than I do.)
1670    
1671     17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
1672     passes PCRE_DOTALL to the pcre_compile() function, making the "." character
1673     match everything, including newlines. This is not POSIX-compatible, but
1674     somebody wanted the feature. From pcretest it can be activated by using
1675     both the P and the s flags.
1676    
1677     18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
1678    
1679     19. libpcre.pc was being incorrectly installed as executable.
1680    
1681     20. A couple of places in pcretest check for end-of-line by looking for '\n';
1682     it now also looks for '\r' so that it will work unmodified on Windows.
1683    
1684     21. Added Google's contributed C++ wrapper to the distribution.
1685    
1686     22. Added some untidy missing memory free() calls in pcretest, to keep
1687     Electric Fence happy when testing.
1688    
1689    
1690    
1691 nigel 75 Version 5.0 13-Sep-04
1692     ---------------------
1693    
1694     1. Internal change: literal characters are no longer packed up into items
1695     containing multiple characters in a single byte-string. Each character
1696     is now matched using a separate opcode. However, there may be more than one
1697     byte in the character in UTF-8 mode.
1698    
1699     2. The pcre_callout_block structure has two new fields: pattern_position and
1700     next_item_length. These contain the offset in the pattern to the next match
1701     item, and its length, respectively.
1702    
1703     3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
1704     insertion of callouts before each pattern item. Added the /C option to
1705     pcretest to make use of this.
1706    
1707     4. On the advice of a Windows user, the lines
1708    
1709     #if defined(_WIN32) || defined(WIN32)
1710     _setmode( _fileno( stdout ), 0x8000 );
1711     #endif /* defined(_WIN32) || defined(WIN32) */
1712    
1713     have been added to the source of pcretest. This apparently does useful
1714     magic in relation to line terminators.
1715    
1716     5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
1717     for the benefit of those environments where the "b" makes a difference.
1718    
1719     6. The icc compiler has the same options as gcc, but "configure" doesn't seem
1720     to know about it. I have put a hack into configure.in that adds in code
1721     to set GCC=yes if CC=icc. This seems to end up at a point in the
1722     generated configure script that is early enough to affect the setting of
1723     compiler options, which is what is needed, but I have no means of testing
1724     whether it really works. (The user who reported this had patched the
1725     generated configure script, which of course I cannot do.)
1726    
1727     LATER: After change 22 below (new libtool files), the configure script
1728     seems to know about icc (and also ecc). Therefore, I have commented out
1729     this hack in configure.in.
1730    
1731     7. Added support for pkg-config (2 patches were sent in).
1732    
1733     8. Negated POSIX character classes that used a combination of internal tables
1734     were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
1735     [[:^ascii]]. Typically, they would match almost any characters. The other
1736     POSIX classes were not broken in this way.
1737    
1738     9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
1739     to find the match, as PCRE was deluded into thinking that the match had to
1740     start at the start point or following a newline. The same bug applied to
1741     patterns with negative forward assertions or any backward assertions
1742     preceding ".*" at the start, unless the pattern required a fixed first
1743     character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
1744    
1745     10. In UTF-8 mode, when moving forwards in the subject after a failed match
1746     starting at the last subject character, bytes beyond the end of the subject
1747     string were read.
1748    
1749     11. Renamed the variable "class" as "classbits" to make life easier for C++
1750     users. (Previously there was a macro definition, but it apparently wasn't
1751     enough.)
1752    
1753     12. Added the new field "tables" to the extra data so that tables can be passed
1754     in at exec time, or the internal tables can be re-selected. This allows
1755     a compiled regex to be saved and re-used at a later time by a different
1756     program that might have everything at different addresses.
1757    
1758     13. Modified the pcre-config script so that, when run on Solaris, it shows a
1759     -R library as well as a -L library.
1760    
1761     14. The debugging options of pcretest (-d on the command line or D on a
1762     pattern) showed incorrect output for anything following an extended class
1763     that contained multibyte characters and which was followed by a quantifier.
1764    
1765     15. Added optional support for general category Unicode character properties
1766     via the \p, \P, and \X escapes. Unicode property support implies UTF-8
1767     support. It adds about 90K to the size of the library. The meanings of the
1768     inbuilt class escapes such as \d and \s have NOT been changed.
1769    
1770     16. Updated pcredemo.c to include calls to free() to release the memory for the
1771     compiled pattern.
1772    
1773     17. The generated file chartables.c was being created in the source directory
1774     instead of in the building directory. This caused the build to fail if the
1775     source directory was different from the building directory, and was
1776     read-only.
1777    
1778     18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
1779     file. No doubt somebody will tell me if they don't make sense... Also added
1780     Dan Mooney's comments about building on OpenVMS.
1781    
1782     19. Added support for partial matching via the PCRE_PARTIAL option for
1783     pcre_exec() and the \P data escape in pcretest.
1784    
1785     20. Extended pcretest with 3 new pattern features:
1786    
1787     (i) A pattern option of the form ">rest-of-line" causes pcretest to
1788     write the compiled pattern to the file whose name is "rest-of-line".
1789     This is a straight binary dump of the data, with the saved pointer to
1790     the character tables forced to be NULL. The study data, if any, is
1791     written too. After writing, pcretest reads a new pattern.
1792    
1793     (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
1794     compiled pattern from the given file. There must not be any
1795     occurrences of "<" in the file name (pretty unlikely); if there are,
1796     pcretest will instead treat the initial "<" as a pattern delimiter.
1797     After reading in the pattern, pcretest goes on to read data lines as
1798     usual.
1799    
1800     (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
1801     and 16-bit fields in a compiled pattern, to simulate a pattern that
1802     was compiled on a host of opposite endianness.
1803    
1804     21. The pcre-exec() function can now cope with patterns that were compiled on
1805     hosts of opposite endianness, with this restriction:
1806    
1807     As for any compiled expression that is saved and used later, the tables
1808     pointer field cannot be preserved; the extra_data field in the arguments
1809     to pcre_exec() should be used to pass in a tables address if a value
1810     other than the default internal tables were used at compile time.
1811    
1812     22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
1813     now diagnosed as an error. Previously, most of the time, a negative number
1814     would have been treated as zero, but if in addition "ovector" was passed as
1815     NULL, a crash could occur.
1816    
1817     23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
1818     new versions from the libtool 1.5 distribution (the last one is a copy of
1819     a file called libtool.m4). This seems to have fixed the need to patch
1820     "configure" to support Darwin 1.3 (which I used to do). However, I still
1821     had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
1822     workstation).
1823    
1824     24. Changed the PCRE licence to be the more standard "BSD" licence.
1825    
1826    
1827 nigel 73 Version 4.5 01-Dec-03
1828     ---------------------
1829    
1830     1. There has been some re-arrangement of the code for the match() function so
1831     that it can be compiled in a version that does not call itself recursively.
1832     Instead, it keeps those local variables that need separate instances for
1833     each "recursion" in a frame on the heap, and gets/frees frames whenever it
1834     needs to "recurse". Keeping track of where control must go is done by means
1835     of setjmp/longjmp. The whole thing is implemented by a set of macros that
1836     hide most of the details from the main code, and operates only if
1837     NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
1838     "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
1839     operating.
1840    
1841     To make it easier for callers to provide specially tailored get/free
1842     functions for this usage, two new functions, pcre_stack_malloc, and
1843     pcre_stack_free, are used. They are always called in strict stacking order,
1844     and the size of block requested is always the same.
1845    
1846     The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
1847     PCRE has been compiled to use the stack or the heap for recursion. The
1848     -C option of pcretest uses this to show which version is compiled.
1849    
1850     A new data escape \S, is added to pcretest; it causes the amounts of store
1851     obtained and freed by both kinds of malloc/free at match time to be added
1852     to the output.
1853    
1854     2. Changed the locale test to use "fr_FR" instead of "fr" because that's
1855     what's available on my current Linux desktop machine.
1856    
1857     3. When matching a UTF-8 string, the test for a valid string at the start has
1858     been extended. If start_offset is not zero, PCRE now checks that it points
1859     to a byte that is the start of a UTF-8 character. If not, it returns
1860     PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
1861     this is necessary because there may be backward assertions in the pattern.
1862     When matching the same subject several times, it may save resources to use
1863     PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
1864    
1865     4. The code for checking the validity of UTF-8 strings has been tightened so
1866     that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
1867     containing "overlong sequences".
1868    
1869     5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
1870     I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
1871     should have been "&", but it just so happened that all the cases this let
1872     through by mistake were picked up later in the function.
1873    
1874     6. I had used a variable called "isblank" - this is a C99 function, causing
1875     some compilers to warn. To avoid this, I renamed it (as "blankclass").
1876    
1877     7. Cosmetic: (a) only output another newline at the end of pcretest if it is
1878     prompting; (b) run "./pcretest /dev/null" at the start of the test script
1879     so the version is shown; (c) stop "make test" echoing "./RunTest".
1880    
1881     8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
1882    
1883     9. The prototype for memmove() for systems that don't have it was using
1884     size_t, but the inclusion of the header that defines size_t was later. I've
1885     moved the #includes for the C headers earlier to avoid this.
1886    
1887     10. Added some adjustments to the code to make it easier to compiler on certain
1888     special systems:
1889    
1890     (a) Some "const" qualifiers were missing.
1891     (b) Added the macro EXPORT before all exported functions; by default this
1892     is defined to be empty.
1893     (c) Changed the dftables auxiliary program (that builds chartables.c) so
1894     that it reads its output file name as an argument instead of writing
1895     to the standard output and assuming this can be redirected.
1896    
1897     11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
1898     class containing characters with values greater than 255, PCRE compilation
1899     went into a loop.
1900    
1901     12. A recursive reference to a subpattern that was within another subpattern
1902     that had a minimum quantifier of zero caused PCRE to crash. For example,
1903     (x(y(?2))z)? provoked this bug with a subject that got as far as the
1904     recursion. If the recursively-called subpattern itself had a zero repeat,
1905     that was OK.
1906    
1907     13. In pcretest, the buffer for reading a data line was set at 30K, but the
1908     buffer into which it was copied (for escape processing) was still set at
1909     1024, so long lines caused crashes.
1910    
1911     14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
1912     "internal error: code overflow...". This applied to any character class
1913     that was followed by a possessive quantifier.
1914    
1915     15. Modified the Makefile to add libpcre.la as a prerequisite for
1916     libpcreposix.la because I was told this is needed for a parallel build to
1917     work.
1918    
1919     16. If a pattern that contained .* following optional items at the start was
1920     studied, the wrong optimizing data was generated, leading to matching
1921     errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
1922     matching string must start with a or b or c. The correct conclusion for
1923     this pattern is that a match can start with any character.
1924    
1925    
1926 nigel 71 Version 4.4 13-Aug-03
1927     ---------------------
1928    
1929     1. In UTF-8 mode, a character class containing characters with values between
1930     127 and 255 was not handled correctly if the compiled pattern was studied.
1931     In fixing this, I have also improved the studying algorithm for such
1932     classes (slightly).
1933    
1934     2. Three internal functions had redundant arguments passed to them. Removal
1935     might give a very teeny performance improvement.
1936    
1937     3. Documentation bug: the value of the capture_top field in a callout is *one
1938     more than* the number of the hightest numbered captured substring.
1939    
1940     4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
1941     in incorrectly linking with a previously installed version. They now link
1942     explicitly with libpcre.la.
1943    
1944     5. configure.in no longer needs to recognize Cygwin specially.
1945    
1946     6. A problem in pcre.in for Windows platforms is fixed.
1947    
1948     7. If a pattern was successfully studied, and the -d (or /D) flag was given to
1949     pcretest, it used to include the size of the study block as part of its
1950     output. Unfortunately, the structure contains a field that has a different
1951     size on different hardware architectures. This meant that the tests that
1952     showed this size failed. As the block is currently always of a fixed size,
1953     this information isn't actually particularly useful in pcretest output, so
1954     I have just removed it.
1955    
1956     8. Three pre-processor statements accidentally did not start in column 1.
1957     Sadly, there are *still* compilers around that complain, even though
1958     standard C has not required this for well over a decade. Sigh.
1959    
1960     9. In pcretest, the code for checking callouts passed small integers in the
1961     callout_data field, which is a void * field. However, some picky compilers
1962     complained about the casts involved for this on 64-bit systems. Now
1963     pcretest passes the address of the small integer instead, which should get
1964     rid of the warnings.
1965    
1966     10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
1967     both compile and run time, and gives an error if an invalid UTF-8 sequence
1968     is found. There is a option for disabling this check in cases where the
1969     string is known to be correct and/or the maximum performance is wanted.
1970    
1971     11. In response to a bug report, I changed one line in Makefile.in from
1972    
1973     -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
1974     to
1975     -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
1976    
1977     to look similar to other lines, but I have no way of telling whether this
1978     is the right thing to do, as I do not use Windows. No doubt I'll get told
1979     if it's wrong...
1980    
1981    
1982 nigel 69 Version 4.3 21-May-03
1983     ---------------------
1984    
1985     1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
1986     Makefile.
1987    
1988     2. Some refactoring to improve the quality of the code:
1989    
1990     (i) The utf8_table... variables are now declared "const".
1991    
1992     (ii) The code for \cx, which used the "case flipping" table to upper case
1993     lower case letters, now just substracts 32. This is ASCII-specific,
1994     but the whole concept of \cx is ASCII-specific, so it seems
1995     reasonable.
1996    
1997     (iii) PCRE was using its character types table to recognize decimal and
1998     hexadecimal digits in the pattern. This is silly, because it handles
1999     only 0-9, a-f, and A-F, but the character types table is locale-
2000     specific, which means strange things might happen. A private
2001     table is now used for this - though it costs 256 bytes, a table is
2002     much faster than multiple explicit tests. Of course, the standard
2003     character types table is still used for matching digits in subject
2004     strings against \d.
2005    
2006     (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
2007     ending in _t are). So I've renamed it as ESC_tee.
2008    
2009     3. The first argument for regexec() in the POSIX wrapper should have been
2010     defined as "const".
2011    
2012     4. Changed pcretest to use malloc() for its buffers so that they can be
2013     Electric Fenced for debugging.
2014    
2015     5. There were several places in the code where, in UTF-8 mode, PCRE would try
2016     to read one or more bytes before the start of the subject string. Often this
2017     had no effect on PCRE's behaviour, but in some circumstances it could
2018     provoke a segmentation fault.
2019    
2020     6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
2021     to try to read one or more bytes before the start of the subject string.
2022    
2023     7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
2024     UTF-8 support could misbehave in various ways if the subject string
2025     contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
2026     area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
2027     back over UTF-8 characters.)
2028    
2029    
2030 nigel 67 Version 4.2 14-Apr-03
2031     ---------------------
2032    
2033     1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
2034    
2035     2. Changes to the building process, supplied by Ronald Landheer-Cieslak
2036     [ON_WINDOWS]: new variable, "#" on non-Windows platforms
2037     [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
2038     [WIN_PREFIX]: new variable, "cyg" for Cygwin
2039     * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
2040     and BUILD_EXEEXT
2041     Note: automatic setting of the BUILD variables is not yet working
2042     set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
2043     compile-time but not at link-time
2044     [LINK]: use for linking executables only
2045     make different versions for Windows and non-Windows
2046     [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
2047     libraries
2048     [LINK_FOR_BUILD]: new variable
2049     [OBJEXT]: use throughout
2050     [EXEEXT]: use throughout
2051     <winshared>: new target
2052     <wininstall>: new target
2053     <dftables.o>: use native compiler
2054     <dftables>: use native linker
2055     <install>: handle Windows platform correctly
2056     <clean>: ditto
2057     <check>: ditto
2058     copy DLL to top builddir before testing
2059    
2060     As part of these changes, -no-undefined was removed again. This was reported
2061     to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
2062     in any case.
2063    
2064     3. Some tidies to get rid of compiler warnings:
2065    
2066     . In the match_data structure, match_limit was an unsigned long int, whereas
2067     match_call_count was an int. I've made them both unsigned long ints.
2068    
2069     . In pcretest the fact that a const uschar * doesn't automatically cast to
2070     a void * provoked a warning.
2071    
2072     . Turning on some more compiler warnings threw up some "shadow" variables
2073     and a few more missing casts.
2074    
2075     4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
2076     option, a class that contained a single character with a value between 128
2077     and 255 (e.g. /[\xFF]/) caused PCRE to crash.
2078    
2079     5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
2080     option, a class that contained several characters, but with at least one
2081     whose value was between 128 and 255 caused PCRE to crash.
2082    
2083    
2084 nigel 65 Version 4.1 12-Mar-03
2085     ---------------------
2086 nigel 63
2087 nigel 65 1. Compiling with gcc -pedantic found a couple of places where casts were
2088     needed, and a string in dftables.c that was longer than standard compilers are
2089     required to support.
2090    
2091     2. Compiling with Sun's compiler found a few more places where the code could
2092     be tidied up in order to avoid warnings.
2093    
2094     3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
2095     first of these names is deprecated in the latest Autoconf in favour of the name
2096     CC_FOR_BUILD, because "host" is typically used to mean the system on which the
2097     compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
2098     analogy I have changed it to CFLAGS_FOR_BUILD.
2099    
2100     4. Added -no-undefined to the linking command in the Makefile, because this is
2101     apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
2102     linking step for the pcreposix library.
2103    
2104     5. PCRE was failing to diagnose the case of two named groups with the same
2105     name.
2106    
2107     6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
2108     literal character that is needed in the subject for a match, and scans along to
2109     ensure that it is present before embarking on the full matching process. This
2110     saves time in cases of nested unlimited repeats that are never going to match.
2111     Problem: the scan can take a lot of time if the subject is very long (e.g.
2112     megabytes), thus penalizing straightforward matches. It is now done only if the
2113     amount of subject to be scanned is less than 1000 bytes.
2114    
2115     7. A lesser problem with the same optimization is that it was recording the
2116     first character of an anchored pattern as "needed", thus provoking a search
2117     right along the subject, even when the first match of the pattern was going to
2118     fail. The "needed" character is now not set for anchored patterns, unless it
2119     follows something in the pattern that is of non-fixed length. Thus, it still
2120     fulfils its original purpose of finding quick non-matches in cases of nested
2121     unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
2122    
2123    
2124     Version 4.0 17-Feb-03
2125     ---------------------
2126    
2127 nigel 63 1. If a comment in an extended regex that started immediately after a meta-item
2128     extended to the end of string, PCRE compiled incorrect data. This could lead to
2129     all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
2130    
2131     2. Moved to autoconf 2.53 and libtool 1.4.2.
2132    
2133     3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
2134     the special perltest8 script is no longer needed - all the tests can be run
2135     from a single perltest script.
2136    
2137     4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
2138     by \s. It has now been removed in PCRE. This means it isn't recognized as
2139     whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
2140     class [:space:] *does* include VT, thereby creating a mess.
2141    
2142     5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
2143     space and tab.
2144    
2145     6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
2146     its new features into the main test script, reducing the number of scripts.
2147    
2148     7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
2149     were backward compatible, and made the (?i) apply to the whole pattern, as if
2150     /i were given. Now it behaves more logically, and applies the option setting
2151     only to what follows. PCRE has been changed to follow suit. However, if it
2152     finds options settings right at the start of the pattern, it extracts them into
2153     the global options, as before. Thus, they show up in the info data.
2154    
2155     8. Added support for the \Q...\E escape sequence. Characters in between are
2156     treated as literals. This is slightly different from Perl in that $ and @ are
2157     also handled as literals inside the quotes. In Perl, they will cause variable
2158     interpolation. Note the following examples:
2159    
2160     Pattern PCRE matches Perl matches
2161    
2162     \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
2163     \Qabc\$xyz\E abc\$xyz abc\$xyz
2164     \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
2165    
2166     For compatibility with Perl, \Q...\E sequences are recognized inside character
2167     classes as well as outside them.
2168    
2169     9. Re-organized 3 code statements in pcretest to avoid "overflow in
2170     floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
2171     (size_t) cast to one statement in pcretest and one in pcreposix to avoid
2172     signed/unsigned warnings.
2173    
2174     10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
2175     option for pcretest, so I've replaced it by a simple function that does just
2176     that job.
2177    
2178     11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
2179     "pcregrep -".
2180    
2181     12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
2182     Java package. This provides some syntactic sugar for simple cases of what my
2183     documentation calls "once-only subpatterns". A pattern such as x*+ is the same
2184     as (?>x*). In other words, if what is inside (?>...) is just a single repeated
2185     item, you can use this simplified notation. Note that only makes sense with
2186     greedy quantifiers. Consequently, the use of the possessive quantifier forces
2187     greediness, whatever the setting of the PCRE_UNGREEDY option.
2188    
2189     13. A change of greediness default within a pattern was not taking effect at
2190     the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
2191     subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
2192     was abstracted outside.
2193    
2194     14. PCRE now supports the \G assertion. It is true when the current matching
2195     position is at the start point of the match. This differs from \A when the
2196     starting offset is non-zero. Used with the /g option of pcretest (or similar
2197     code), it works in the same way as it does for Perl's /g option. If all
2198     alternatives of a regex begin with \G, the expression is anchored to the start
2199     match position, and the "anchored" flag is set in the compiled expression.
2200    
2201     15. Some bugs concerning the handling of certain option changes within patterns
2202     have been fixed. These applied to options other than (?ims). For example,
2203     "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
2204     been the other way round. Some of this was related to change 7 above.
2205    
2206     16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
2207     features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
2208     and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
2209     POSIX classes only within a class (e.g. /[[:alpha:]]/).
2210    
2211     17. Added support for Perl's \C escape. This matches one byte, even in UTF8
2212     mode. Unlike ".", it always matches newline, whatever the setting of
2213     PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
2214     assertions. Perl allows it, but it doesn't (in general) work because it can't
2215     calculate the length of the lookbehind. At least, that's the case for Perl
2216     5.8.0 - I've been told they are going to document that it doesn't work in
2217     future.
2218    
2219     18. Added an error diagnosis for escapes that PCRE does not support: these are
2220     \L, \l, \N, \P, \p, \U, \u, and \X.
2221    
2222     19. Although correctly diagnosing a missing ']' in a character class, PCRE was
2223     reading past the end of the pattern in cases such as /[abcd/.
2224    
2225     20. PCRE was getting more memory than necessary for patterns with classes that
2226     contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
2227    
2228     21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
2229     compiling PCRE for use with Virtual Pascal.
2230    
2231     22. Small fix to the Makefile to make it work properly if the build is done
2232     outside the source tree.
2233    
2234     23. Added a new extension: a condition to go with recursion. If a conditional
2235     subpattern starts with (?(R) the "true" branch is used if recursion has
2236     happened, whereas the "false" branch is used only at the top level.
2237    
2238     24. When there was a very long string of literal characters (over 255 bytes
2239     without UTF support, over 250 bytes with UTF support), the computation of how
2240     much memory was required could be incorrect, leading to segfaults or other
2241     strange effects.
2242    
2243     25. PCRE was incorrectly assuming anchoring (either to start of subject or to
2244     start of line for a non-DOTALL pattern) when a pattern started with (.*) and
2245     there was a subsequent back reference to those brackets. This meant that, for
2246     example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
2247     possible to check for precisely this case. All we can do is abandon the
2248     optimization if .* occurs inside capturing brackets when there are any back
2249     references whatsoever. (See below for a better fix that came later.)
2250    
2251     26. The handling of the optimization for finding the first character of a
2252     non-anchored pattern, and for finding a character that is required later in the
2253     match were failing in some cases. This didn't break the matching; it just
2254     failed to optimize when it could. The way this is done has been re-implemented.
2255    
2256     27. Fixed typo in error message for invalid (?R item (it said "(?p").
2257    
2258     28. Added a new feature that provides some of the functionality that Perl
2259     provides with (?{...}). The facility is termed a "callout". The way it is done
2260     in PCRE is for the caller to provide an optional function, by setting
2261     pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
2262     global variable. By default it is unset, which disables all calling out. To get
2263     the function called, the regex must include (?C) at appropriate points. This
2264     is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
2265     This provides a means of identifying different callout points. When PCRE
2266     reaches such a point in the regex, if pcre_callout has been set, the external
2267     function is called. It is provided with data in a structure called
2268     pcre_callout_block, which is defined in pcre.h. If the function returns 0,
2269     matching continues; if it returns a non-zero value, the match at the current
2270     point fails. However, backtracking will occur if possible. [This was changed
2271     later and other features added - see item 49 below.]
2272    
2273     29. pcretest is upgraded to test the callout functionality. It provides a
2274     callout function that displays information. By default, it shows the start of
2275     the match and the current position in the text. There are some new data escapes
2276     to vary what happens:
2277    
2278     \C+ in addition, show current contents of captured substrings
2279     \C- do not supply a callout function
2280     \C!n return 1 when callout number n is reached
2281     \C!n!m return 1 when callout number n is reached for the mth time
2282    
2283     30. If pcregrep was called with the -l option and just a single file name, it
2284     output "<stdin>" if a match was found, instead of the file name.
2285    
2286     31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
2287     slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
2288     pcre_exec(). This saves a malloc/free per call. The default value of
2289     POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
2290     when configuring.
2291    
2292     32. The default maximum size of a compiled pattern is 64K. There have been a
2293     few cases of people hitting this limit. The code now uses macros to handle the
2294     storing of links as offsets within the compiled pattern. It defaults to 2-byte
2295     links, but this can be changed to 3 or 4 bytes by --with-link-size when
2296     configuring. Tests 2 and 5 work only with 2-byte links because they output
2297     debugging information about compiled patterns.
2298    
2299     33. Internal code re-arrangements:
2300    
2301     (a) Moved the debugging function for printing out a compiled regex into
2302     its own source file (printint.c) and used #include to pull it into
2303     pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
2304     separate copies.
2305    
2306     (b) Defined the list of op-code names for debugging as a macro in
2307     internal.h so that it is next to the definition of the opcodes.
2308    
2309     (c) Defined a table of op-code lengths for simpler skipping along compiled
2310     code. This is again a macro in internal.h so that it is next to the
2311     definition of the opcodes.
2312    
2313     34. Added support for recursive calls to individual subpatterns, along the
2314     lines of Robin Houston's patch (but implemented somewhat differently).
2315    
2316     35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
2317     allow it to read and process whole directories in Win32. This code was
2318     contributed by Lionel Fourquaux; it has not been tested by me.
2319    
2320     36. Added support for named subpatterns. The Python syntax (?P<name>...) is
2321     used to name a group. Names consist of alphanumerics and underscores, and must
2322     be unique. Back references use the syntax (?P=name) and recursive calls use
2323     (?P>name) which is a PCRE extension to the Python extension. Groups still have
2324     numbers. The function pcre_fullinfo() can be used after compilation to extract
2325     a name/number map. There are three relevant calls:
2326    
2327     PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
2328     PCRE_INFO_NAMECOUNT yields the number of entries
2329     PCRE_INFO_NAMETABLE yields a pointer to the map.
2330    
2331     The map is a vector of fixed-size entries. The size of each entry depends on
2332     the length of the longest name used. The first two bytes of each entry are the
2333     group number, most significant byte first. There follows the corresponding
2334     name, zero terminated. The names are in alphabetical order.
2335    
2336     37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
2337     case instead of 255. Making it the same both with and without UTF-8 support
2338     means that the same test output works with both.
2339    
2340     38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
2341     calling malloc() with a zero argument.
2342    
2343     39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
2344     optimization. I've improved things by keeping a bitmap of backreferences with
2345     numbers 1-31 so that if .* occurs inside capturing brackets that are not in
2346     fact referenced, the optimization can be applied. It is unlikely that a
2347     relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
2348     the match to follow \n) will appear inside brackets with a number greater than
2349     31, but if it does, any back reference > 31 suppresses the optimization.
2350    
2351     40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
2352     of disabling numbered capturing parentheses. Any opening parenthesis that is
2353     not followed by ? behaves as if it were followed by ?: but named parentheses
2354     can still be used for capturing (and they will acquire numbers in the usual
2355     way).
2356    
2357     41. Redesigned the return codes from the match() function into yes/no/error so
2358     that errors can be passed back from deep inside the nested calls. A malloc
2359     failure while inside a recursive subpattern call now causes the
2360     PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
2361    
2362     42. It is now possible to set a limit on the number of times the match()
2363     function is called in a call to pcre_exec(). This facility makes it possible to
2364     limit the amount of recursion and backtracking, though not in a directly
2365     obvious way, because the match() function is used in a number of different
2366     circumstances. The count starts from zero for each position in the subject
2367     string (for non-anchored patterns). The default limit is, for compatibility, a
2368     large number, namely 10 000 000. You can change this in two ways:
2369    
2370     (a) When configuring PCRE before making, you can use --with-match-limit=n
2371     to set a default value for the compiled library.
2372    
2373     (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
2374     a different value is set. See 45 below.
2375    
2376     If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
2377    
2378     43. Added a new function pcre_config(int, void *) to enable run-time extraction
2379     of things that can be changed at compile time. The first argument specifies
2380     what is wanted and the second points to where the information is to be placed.
2381     The current list of available information is:
2382    
2383     PCRE_CONFIG_UTF8
2384    
2385     The output is an integer that is set to one if UTF-8 support is available;
2386     otherwise it is set to zero.
2387    
2388     PCRE_CONFIG_NEWLINE
2389    
2390     The output is an integer that it set to the value of the code that is used for
2391     newline. It is either LF (10) or CR (13).
2392    
2393     PCRE_CONFIG_LINK_SIZE
2394    
2395     The output is an integer that contains the number of bytes used for internal
2396     linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
2397    
2398     PCRE_CONFIG_POSIX_MALLOC_THRESHOLD
2399    
2400     The output is an integer that contains the threshold above which the POSIX
2401     interface uses malloc() for output vectors. See item 31 above.
2402    
2403     PCRE_CONFIG_MATCH_LIMIT
2404    
2405     The output is an unsigned integer that contains the default limit of the number
2406     of match() calls in a pcre_exec() execution. See 42 above.
2407    
2408     44. pcretest has been upgraded by the addition of the -C option. This causes it
2409     to extract all the available output from the new pcre_config() function, and to
2410     output it. The program then exits immediately.
2411    
2412     45. A need has arisen to pass over additional data with calls to pcre_exec() in
2413     order to support additional features. One way would have been to define
2414     pcre_exec2() (for example) with extra arguments, but this would not have been
2415     extensible, and would also have required all calls to the original function to
2416     be mapped to the new one. Instead, I have chosen to extend the mechanism that
2417     is used for passing in "extra" data from pcre_study().
2418    
2419     The pcre_extra structure is now exposed and defined in pcre.h. It currently
2420     contains the following fields:
2421    
2422     flags a bitmap indicating which of the following fields are set
2423     study_data opaque data from pcre_study()
2424     match_limit a way of specifying a limit on match() calls for a specific
2425     call to pcre_exec()
2426     callout_data data for callouts (see 49 below)
2427    
2428     The flag bits are also defined in pcre.h, and are
2429    
2430     PCRE_EXTRA_STUDY_DATA
2431     PCRE_EXTRA_MATCH_LIMIT
2432     PCRE_EXTRA_CALLOUT_DATA
2433    
2434     The pcre_study() function now returns one of these new pcre_extra blocks, with
2435     the actual study data pointed to by the study_data field, and the
2436     PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
2437     before. That is, this change is entirely upwards-compatible and requires no
2438     change to existing code.
2439    
2440     If you want to pass in additional data to pcre_exec(), you can either place it
2441     in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
2442     block.
2443    
2444     46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
2445     data string contains the escape sequence \M, pcretest calls pcre_exec() several
2446     times with different match limits, until it finds the minimum value needed for
2447     pcre_exec() to complete. The value is then output. This can be instructive; for
2448     most simple matches the number is quite small, but for pathological cases it
2449     gets very large very quickly.
2450    
2451     47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
2452     returns the size of the data block pointed to by the study_data field in a
2453     pcre_extra block, that is, the value that was passed as the argument to
2454     pcre_malloc() when PCRE was getting memory in which to place the information
2455     created by pcre_study(). The fourth argument should point to a size_t variable.
2456     pcretest has been extended so that this information is shown after a successful
2457     pcre_study() call when information about the compiled regex is being displayed.
2458    
2459     48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
2460     because what follows is always an absolute path. (Later: it turns out that this
2461     is more than cosmetic for MinGW, because it doesn't like empty path
2462     components.)
2463    
2464     49. Some changes have been made to the callout feature (see 28 above):
2465    
2466     (i) A callout function now has three choices for what it returns:
2467    
2468     0 => success, carry on matching
2469     > 0 => failure at this point, but backtrack if possible
2470     < 0 => serious error, return this value from pcre_exec()
2471    
2472     Negative values should normally be chosen from the set of PCRE_ERROR_xxx
2473     values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
2474     "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
2475     use by callout functions. It will never be used by PCRE itself.
2476    
2477     (ii) The pcre_extra structure (see 45 above) has a void * field called
2478     callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
2479     pcre_callout_block structure has a field of the same name. The contents of
2480     the field passed in the pcre_extra structure are passed to the callout
2481     function in the corresponding field in the callout block. This makes it
2482     easier to use the same callout-containing regex from multiple threads. For
2483     testing, the pcretest program has a new data escape
2484    
2485     \C*n pass the number n (may be negative) as callout_data
2486    
2487     If the callout function in pcretest receives a non-zero value as
2488     callout_data, it returns that value.
2489    
2490     50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
2491     there were some redundant $(CFLAGS) in commands that are now specified as
2492     $(LINK), which already includes $(CFLAGS).
2493    
2494     51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
2495     has been compiled with UTF-8 support *and* pcre_compile() has been compiled
2496     with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
2497     one-byte characters throughout. Note that case-insensitive matching applies
2498     only to characters whose values are less than 256. PCRE doesn't support the
2499     notion of cases for higher-valued characters.
2500    
2501     (i) A character class whose characters are all within 0-255 is handled as
2502     a bit map, and the map is inverted for negative classes. Previously, a
2503     character > 255 always failed to match such a class; however it should
2504     match if the class was a negative one (e.g. [^ab]). This has been fixed.
2505    
2506     (ii) A negated character class with a single character < 255 is coded as
2507     "not this character" (OP_NOT). This wasn't working properly when the test
2508     character was multibyte, either singly or repeated.
2509    
2510     (iii) Repeats of multibyte characters are now handled correctly in UTF-8
2511     mode, for example: \x{100}{2,3}.
2512    
2513     (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
2514     singly or repeated) now correctly test multibyte characters. However,
2515     PCRE doesn't recognize any characters with values greater than 255 as
2516     digits, spaces, or word characters. Such characters always match \D, \S,
2517     and \W, and never match \d, \s, or \w.
2518    
2519     (v) Classes may now contain characters and character ranges with values
2520     greater than 255. For example: [ab\x{100}-\x{400}].
2521    
2522     (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
2523     PCRE in UTF-8 mode.
2524    
2525     52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
2526     PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
2527     retained for backwards compatibility. (Note that LASTLITERAL is also a byte
2528     value.)
2529    
2530     53. The single man page has become too large. I have therefore split it up into
2531     a number of separate man pages. These also give rise to individual HTML pages;
2532     these are now put in a separate directory, and there is an index.html page that
2533     lists them all. Some hyperlinking between the pages has been installed.
2534    
2535     54. Added convenience functions for handling named capturing parentheses.
2536    
2537     55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
2538     aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
2539     true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
2540     are faulted.
2541    
2542     56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
2543     calling configure. These values are used when compiling the dftables.c program
2544     which is run to generate the source of the default character tables. They
2545     default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
2546     you will need to set these values.
2547    
2548     57. Updated the building process for Windows DLL, as provided by Fred Cox.
2549    
2550    
2551     Version 3.9 02-Jan-02
2552 nigel 61 ---------------------
2553    
2554     1. A bit of extraneous text had somehow crept into the pcregrep documentation.
2555    
2556     2. If --disable-static was given, the building process failed when trying to
2557     build pcretest and pcregrep. (For some reason it was using libtool to compile
2558     them, which is not right, as they aren't part of the library.)
2559    
2560    
2561 nigel 59 Version 3.8 18-Dec-01
2562     ---------------------
2563    
2564     1. The experimental UTF-8 code was completely screwed up. It was packing the
2565     bytes in the wrong order. How dumb can you get?
2566    
2567    
2568 nigel 57 Version 3.7 29-Oct-01
2569     ---------------------
2570    
2571     1. In updating pcretest to check change 1 of version 3.6, I screwed up.
2572     This caused pcretest, when used on the test data, to segfault. Unfortunately,
2573     this didn't happen under Solaris 8, where I normally test things.
2574    
2575 nigel 59 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
2576     doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
2577     isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
2578     this fix an hour or so after the initial 3.7 release.)
2579 nigel 57
2580 nigel 59
2581 nigel 55 Version 3.6 23-Oct-01
2582     ---------------------
2583    
2584     1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
2585     offsets passed as NULL with zero offset count.
2586    
2587     2. The config.guess and config.sub files had not been updated when I moved to
2588     the latest autoconf.
2589    
2590    
2591 nigel 53 Version 3.5 15-Aug-01
2592     ---------------------
2593 nigel 5
2594 nigel 53 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
2595     had been forgotten.
2596    
2597     2. By using declared but undefined structures, we can avoid using "void"
2598     definitions in pcre.h while keeping the internal definitions of the structures
2599     private.
2600    
2601     3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
2602     user point of view, this means that both static and shared libraries are built
2603     by default, but this can be individually controlled. More of the work of
2604     handling this static/shared cases is now inside libtool instead of PCRE's make
2605     file.
2606    
2607     4. The pcretest utility is now installed along with pcregrep because it is
2608     useful for users (to test regexs) and by doing this, it automatically gets
2609     relinked by libtool. The documentation has been turned into a man page, so
2610     there are now .1, .txt, and .html versions in /doc.
2611    
2612     5. Upgrades to pcregrep:
2613     (i) Added long-form option names like gnu grep.
2614     (ii) Added --help to list all options with an explanatory phrase.
2615     (iii) Added -r, --recursive to recurse into sub-directories.
2616     (iv) Added -f, --file to read patterns from a file.
2617    
2618     6. pcre_exec() was referring to its "code" argument before testing that
2619     argument for NULL (and giving an error if it was NULL).
2620    
2621     7. Upgraded Makefile.in to allow for compiling in a different directory from
2622     the source directory.
2623    
2624     8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
2625     options bits, the pointer it was passed was to an int instead of to an unsigned
2626     long int. This mattered only on 64-bit systems.
2627    
2628     9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
2629     generated) instead of pcre.in, which it its source. Also made the same change
2630     in several of the .c files.
2631    
2632     10. A new release of gcc defines printf() as a macro, which broke pcretest
2633     because it had an ifdef in the middle of a string argument for printf(). Fixed
2634     by using separate calls to printf().
2635    
2636     11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
2637     script, to force use of CR or LF instead of \n in the source. On non-Unix
2638     systems, the value can be set in config.h.
2639    
2640     12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
2641     absolute limit. Changed the text of the error message to make this clear, and
2642     likewise updated the man page.
2643    
2644     13. The limit of 99 on the number of capturing subpatterns has been removed.
2645     The new limit is 65535, which I hope will not be a "real" limit.
2646    
2647    
2648 nigel 51 Version 3.4 22-Aug-00
2649     ---------------------
2650    
2651     1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
2652    
2653     2. Diagnose condition (?(0) as an error instead of crashing on matching.
2654    
2655    
2656 nigel 49 Version 3.3 01-Aug-00
2657     ---------------------
2658    
2659     1. If an octal character was given, but the value was greater than \377, it
2660     was not getting masked to the least significant bits, as documented. This could
2661     lead to crashes in some systems.
2662    
2663     2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
2664     the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
2665    
2666     3. Added the functions pcre_free_substring() and pcre_free_substring_list().
2667     These just pass their arguments on to (pcre_free)(), but they are provided
2668     because some uses of PCRE bind it to non-C systems that can call its functions,
2669     but cannot call free() or pcre_free() directly.
2670    
2671     4. Add "make test" as a synonym for "make check". Corrected some comments in
2672     the Makefile.
2673    
2674     5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
2675     Makefile.
2676    
2677     6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
2678     command called pgrep for grepping around the active processes.
2679    
2680     7. Added the beginnings of support for UTF-8 character strings.
2681    
2682     8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
2683     RANLIB to ./ltconfig so that they are used by libtool. I think these are all
2684     the relevant ones. (AR is not passed because ./ltconfig does its own figuring
2685     out for the ar command.)
2686    
2687    
2688 nigel 47 Version 3.2 12-May-00
2689     ---------------------
2690    
2691     This is purely a bug fixing release.
2692    
2693     1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
2694     of ZA. This was just one example of several cases that could provoke this bug,
2695     which was introduced by change 9 of version 2.00. The code for breaking
2696     infinite loops after an iteration that matches an empty string was't working
2697     correctly.
2698    
2699     2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
2700     when matched against abbab (for example). After matching an empty string, it
2701     wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
2702     caused it to match further down the string than it should.
2703    
2704     3. The code contained an inclusion of sys/types.h. It isn't clear why this
2705     was there because it doesn't seem to be needed, and it causes trouble on some
2706     systems, as it is not a Standard C header. It has been removed.
2707    
2708     4. Made 4 silly changes to the source to avoid stupid compiler warnings that
2709     were reported on the Macintosh. The changes were from
2710    
2711     while ((c = *(++ptr)) != 0 && c != '\n');
2712     to
2713     while ((c = *(++ptr)) != 0 && c != '\n') ;
2714    
2715     Totally extraordinary, but if that's what it takes...
2716    
2717     5. PCRE is being used in one environment where neither memmove() nor bcopy() is
2718     available. Added HAVE_BCOPY and an autoconf test for it; if neither
2719     HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
2720     assumes the way PCRE uses memmove() (always moving upwards).
2721    
2722     6. PCRE is being used in one environment where strchr() is not available. There
2723     was only one use in pcre.c, and writing it out to avoid strchr() probably gives
2724     faster code anyway.
2725    
2726    
2727 nigel 45 Version 3.1 09-Feb-00
2728     ---------------------
2729    
2730     The only change in this release is the fixing of some bugs in Makefile.in for
2731     the "install" target:
2732    
2733     (1) It was failing to install pcreposix.h.
2734    
2735     (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
2736    
2737    
2738 nigel 43 Version 3.0 01-Feb-00
2739     ---------------------
2740 nigel 41
2741     1. Add support for the /+ modifier to perltest (to output $` like it does in
2742     pcretest).
2743    
2744     2. Add support for the /g modifier to perltest.
2745    
2746     3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
2747     matches null strings.
2748    
2749     4. Fix perltest so that it doesn't do unwanted things when fed an empty
2750     pattern. Perl treats empty patterns specially - it reuses the most recent
2751     pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
2752     effect.
2753    
2754     5. The POSIX interface was broken in that it was just handing over the POSIX
2755     captured string vector to pcre_exec(), but (since release 2.00) PCRE has
2756     required a bigger vector, with some working space on the end. This means that
2757     the POSIX wrapper now has to get and free some memory, and copy the results.
2758    
2759 nigel 43 6. Added some simple autoconf support, placing the test data and the
2760     documentation in separate directories, re-organizing some of the
2761     information files, and making it build pcre-config (a GNU standard). Also added
2762     libtool support for building PCRE as a shared library, which is now the
2763     default.
2764 nigel 41
2765 nigel 43 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
2766     09 are not valid octal constants. Single digits will be used for minor values
2767     less than 10.
2768    
2769     8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
2770     existing programs that set these in the POSIX interface can use PCRE without
2771     modification.
2772    
2773     9. Added a new function, pcre_fullinfo() with an extensible interface. It can
2774     return all that pcre_info() returns, plus additional data. The pcre_info()
2775     function is retained for compatibility, but is considered to be obsolete.
2776    
2777     10. Added experimental recursion feature (?R) to handle one common case that
2778     Perl 5.6 will be able to do with (?p{...}).
2779    
2780     11. Added support for POSIX character classes like [:alpha:], which Perl is
2781     adopting.
2782    
2783    
2784 nigel 39 Version 2.08 31-Aug-99
2785     ----------------------
2786    
2787     1. When startoffset was not zero and the pattern began with ".*", PCRE was not
2788     trying to match at the startoffset position, but instead was moving forward to
2789     the next newline as if a previous match had failed.
2790    
2791     2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
2792     and could get into a loop if a null string was matched other than at the start
2793     of the subject.
2794    
2795     3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
2796     be distinguished at compile time, and for completeness also added PCRE_DATE.
2797    
2798     5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
2799     in GnuWin32 environments.
2800    
2801    
2802 nigel 37 Version 2.07 29-Jul-99
2803     ----------------------
2804    
2805     1. The documentation is now supplied in plain text form and HTML as well as in
2806     the form of man page sources.
2807    
2808     2. C++ compilers don't like assigning (void *) values to other pointer types.
2809     In particular this affects malloc(). Although there is no problem in Standard
2810     C, I've put in casts to keep C++ compilers happy.
2811    
2812     3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
2813     should be (const char *).
2814    
2815     4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
2816     be useful for non-Unix systems who don't want to bother with the POSIX stuff.
2817     However, I haven't made this a standard facility. The documentation doesn't
2818     mention it, and the Makefile doesn't support it.
2819    
2820     5. The Makefile now contains an "install" target, with editable destinations at
2821     the top of the file. The pcretest program is not installed.
2822    
2823     6. pgrep -V now gives the PCRE version number and date.
2824    
2825     7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
2826     causing the entire string to be ignored, instead of just the last character.
2827    
2828     8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
2829     non-matching string, it can take a very, very long time, even for strings of
2830     quite modest length, because of the nested recursion. PCRE now does better in
2831     some of these cases. It does this by remembering the last required literal
2832     character in the pattern, and pre-searching the subject to ensure it is present
2833     before running the real match. In other words, it applies a heuristic to detect
2834     some types of certain failure quickly, and in the above example, if presented
2835     with a string that has no trailing " it gives "no match" very quickly.
2836    
2837     9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
2838     other alternatives are tried instead.
2839    
2840    
2841 nigel 35 Version 2.06 09-Jun-99
2842     ----------------------
2843    
2844     1. Change pcretest's output for amount of store used to show just the code
2845     space, because the remainder (the data block) varies in size between 32-bit and
2846     64-bit systems.
2847    
2848     2. Added an extra argument to pcre_exec() to supply an offset in the subject to
2849     start matching at. This allows lookbehinds to work when searching for multiple
2850     occurrences in a string.
2851    
2852     3. Added additional options to pcretest for testing multiple occurrences:
2853    
2854     /+ outputs the rest of the string that follows a match
2855     /g loops for multiple occurrences, using the new startoffset argument
2856     /G loops for multiple occurrences by passing an incremented pointer
2857    
2858     4. PCRE wasn't doing the "first character" optimization for patterns starting
2859     with \b or \B, though it was doing it for other lookbehind assertions. That is,
2860     it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
2861     the letter 'x'. On long subject strings, this gives a significant speed-up.
2862    
2863    
2864 nigel 33 Version 2.05 21-Apr-99
2865     ----------------------
2866    
2867     1. Changed the type of magic_number from int to long int so that it works
2868     properly on 16-bit systems.
2869    
2870     2. Fixed a bug which caused patterns starting with .* not to work correctly
2871     when the subject string contained newline characters. PCRE was assuming
2872     anchoring for such patterns in all cases, which is not correct because .* will
2873     not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
2874     DOTALL is set at top level; otherwise it knows that patterns starting with .*
2875     must be retried after every newline in the subject.
2876    
2877    
2878 nigel 31 Version 2.04 18-Feb-99
2879     ----------------------
2880    
2881     1. For parenthesized subpatterns with repeats whose minimum was zero, the
2882     computation of the store needed to hold the pattern was incorrect (too large).
2883     If such patterns were nested a few deep, this could multiply and become a real
2884     problem.
2885    
2886     2. Added /M option to pcretest to show the memory requirement of a specific
2887     pattern. Made -m a synonym of -s (which does this globally) for compatibility.
2888    
2889     3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
2890     compiled in such a way that the backtracking after subsequent failure was
2891     pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
2892     ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
2893    
2894    
2895 nigel 29 Version 2.03 02-Feb-99
2896     ----------------------
2897    
2898     1. Fixed typo and small mistake in man page.
2899    
2900 nigel 31 2. Added 4th condition (GPL supersedes if conflict) and created separate
2901     LICENCE file containing the conditions.
2902 nigel 29
2903     3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
2904     Perl, that is the internal \ allows the delimiter to be included in the
2905     pattern. Locked out the use of \ as a delimiter. If \ immediately follows
2906     the final delimiter, add \ to the end of the pattern (to test the error).
2907    
2908     4. Added the convenience functions for extracting substrings after a successful
2909     match. Updated pcretest to make it able to test these functions.
2910    
2911    
2912 nigel 27 Version 2.02 14-Jan-99
2913     ----------------------
2914    
2915     1. Initialized the working variables associated with each extraction so that
2916     their saving and restoring doesn't refer to uninitialized store.
2917    
2918     2. Put dummy code into study.c in order to trick the optimizer of the IBM C
2919     compiler for OS/2 into generating correct code. Apparently IBM isn't going to
2920     fix the problem.
2921    
2922     3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
2923     calls, and wasn't printing the correct value for compiling calls. Increased the
2924     default value of LOOPREPEAT, and the number of significant figures in the
2925     times.
2926    
2927     4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
2928    
2929     5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
2930     a building problem on Windows NT with a FAT file system.
2931    
2932    
2933 nigel 25 Version 2.01 21-Oct-98
2934     ----------------------
2935    
2936     1. Changed the API for pcre_compile() to allow for the provision of a pointer
2937     to character tables built by pcre_maketables() in the current locale. If NULL
2938     is passed, the default tables are used.
2939    
2940    
2941 nigel 23 Version 2.00 24-Sep-98
2942 nigel 21 ----------------------
2943    
2944 nigel 23 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
2945     it any more.
2946    
2947     2. Allow quantification of (?>) groups, and make it work correctly.
2948    
2949     3. The first character computation wasn't working for (?>) groups.
2950    
2951     4. Correct the implementation of \Z (it is permitted to match on the \n at the
2952     end of the subject) and add 5.005's \z, which really does match only at the
2953     very end of the subject.
2954    
2955     5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
2956    
2957     6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
2958     DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
2959     localized options. All options to pcre_study() were also removed.
2960    
2961     7. Add other new features from 5.005:
2962    
2963     $(?<= positive lookbehind
2964     $(?<! negative lookbehind
2965     (?imsx-imsx) added the unsetting capability
2966     such a setting is global if at outer level; local otherwise
2967     (?imsx-imsx:) non-capturing groups with option setting
2968     (?(cond)re|re) conditional pattern matching
2969    
2970     A backreference to itself in a repeated group matches the previous
2971     captured string.
2972    
2973     8. General tidying up of studying (both automatic and via "study")
2974     consequential on the addition of new assertions.
2975    
2976     9. As in 5.005, unlimited repeated groups that could match an empty substring
2977     are no longer faulted at compile time. Instead, the loop is forcibly broken at
2978     runtime if any iteration does actually match an empty substring.
2979    
2980     10. Include the RunTest script in the distribution.
2981    
2982     11. Added tests from the Perl 5.005_02 distribution. This showed up a few
2983     discrepancies, some of which were old and were also with respect to 5.004. They
2984     have now been fixed.
2985    
2986    
2987     Version 1.09 28-Apr-98
2988     ----------------------
2989    
2990 nigel 21 1. A negated single character class followed by a quantifier with a minimum
2991     value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
2992     program crashes, or just wrong answers. This did not apply to negated classes
2993     containing more than one character, or to minima other than one.
2994    
2995    
2996 nigel 19 Version 1.08 27-Mar-98
2997     ----------------------
2998    
2999     1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
3000    
3001     2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
3002     latter must appear before anything that relies on it in the pattern.
3003    
3004    
3005 nigel 17 Version 1.07 16-Feb-98
3006     ----------------------
3007    
3008     1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
3009     repeat of a potentially empty string).
3010    
3011    
3012 nigel 15 Version 1.06 23-Jan-98
3013     ----------------------
3014    
3015     1. Added Markus Oberhumer's little patches for C++.
3016    
3017     2. Literal strings longer than 255 characters were broken.
3018    
3019    
3020 nigel 13 Version 1.05 23-Dec-97
3021     ----------------------
3022    
3023     1. Negated character classes containing more than one character were failing if
3024     PCRE_CASELESS was set at run time.
3025    
3026    
3027 nigel 11 Version 1.04 19-Dec-97
3028     ----------------------
3029    
3030     1. Corrected the man page, where some "const" qualifiers had been omitted.
3031    
3032     2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
3033     input syntax.
3034    
3035     3. Fixed memory leak which occurred when a regex with back references was
3036     matched with an offsets vector that wasn't big enough. The temporary memory
3037     that is used in this case wasn't being freed if the match failed.
3038    
3039     4. Tidied pcretest to ensure it frees memory that it gets.
3040    
3041     5. Temporary memory was being obtained in the case where the passed offsets
3042     vector was exactly big enough.
3043    
3044     6. Corrected definition of offsetof() from change 5 below.
3045    
3046     7. I had screwed up change 6 below and broken the rules for the use of
3047     setjmp(). Now fixed.
3048    
3049    
3050 nigel 9 Version 1.03 18-Dec-97
3051     ----------------------
3052    
3053     1. A erroneous regex with a missing opening parenthesis was correctly
3054     diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
3055     on some systems.
3056    
3057     2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
3058     it was reported that one broken compiler failed on the former because "code" is
3059     also an independent variable.
3060    
3061     3. The erroneous regex a[]b caused an array overrun reference.
3062    
3063     4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
3064     fail on data ending with that character. (It was going on too far, and checking
3065     the next character, typically a binary zero.) This was specific to the
3066     optimized code for single-character negative classes.
3067    
3068     5. Added a contributed patch from the TIN world which does the following:
3069    
3070     + Add an undef for memmove, in case the the system defines a macro for it.
3071    
3072     + Add a definition of offsetof(), in case there isn't one. (I don't know
3073     the reason behind this - offsetof() is part of the ANSI standard - but
3074     it does no harm).
3075    
3076     + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
3077     most of the places where whitespace preceded '#'. I have given up and
3078     allowed the remaining 2 cases to be at the margin.
3079    
3080     + Rename some variables in pcre to eliminate shadowing. This seems very
3081     pedantic, but does no harm, of course.
3082    
3083     6. Moved the call to setjmp() into its own function, to get rid of warnings
3084     from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
3085    
3086     7. Constructs such as \d{8,} were compiling into the equivalent of
3087 nigel 11 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
3088 nigel 9 outcome, but in this particular case used more store than had been allocated,
3089     which caused the bug to be discovered because it threw up an internal error.
3090    
3091     8. The debugging code in both pcre and pcretest for outputting the compiled
3092     form of a regex was going wrong in the case of back references followed by
3093     curly-bracketed repeats.
3094    
3095    
3096 nigel 7 Version 1.02 12-Dec-97
3097     ----------------------
3098    
3099     1. Typos in pcre.3 and comments in the source fixed.
3100    
3101     2. Applied a contributed patch to get rid of places where it used to remove
3102     'const' from variables, and fixed some signed/unsigned and uninitialized
3103     variable warnings.
3104    
3105     3. Added the "runtest" target to Makefile.
3106    
3107     4. Set default compiler flag to -O2 rather than just -O.
3108    
3109    
3110 nigel 5 Version 1.01 19-Nov-97
3111     ----------------------
3112    
3113     1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
3114     like /([ab]*)*/, that is, for classes with more than one character in them.
3115    
3116     2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
3117     as /((?>a*))*/ (a PCRE_EXTRA facility).
3118    
3119    
3120     Version 1.00 18-Nov-97
3121     ----------------------
3122    
3123     1. Added compile-time macros to support systems such as SunOS4 which don't have
3124     memmove() or strerror() but have other things that can be used instead.
3125    
3126     2. Arranged that "make clean" removes the executables.
3127    
3128    
3129 nigel 3 Version 0.99 27-Oct-97
3130     ----------------------
3131    
3132     1. Fixed bug in code for optimizing classes with only one character. It was
3133     initializing a 32-byte map regardless, which could cause it to run off the end
3134     of the memory it had got.
3135    
3136     2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
3137    
3138    
3139     Version 0.98 22-Oct-97
3140     ----------------------
3141    
3142     1. Fixed bug in code for handling temporary memory usage when there are more
3143     back references than supplied space in the ovector. This could cause segfaults.
3144    
3145    
3146     Version 0.97 21-Oct-97
3147     ----------------------
3148    
3149     1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
3150    
3151     2. Optimized negated single characters not to use a bit map.
3152    
3153     3. Brought error texts together as macro definitions; clarified some of them;
3154     fixed one that was wrong - it said "range out of order" when it meant "invalid
3155     escape sequence".
3156    
3157     4. Changed some char * arguments to const char *.
3158    
3159     5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
3160    
3161     6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
3162     pcretest.
3163    
3164    
3165     Version 0.96 16-Oct-97
3166     ----------------------
3167    
3168     1. Added a simple "pgrep" utility to the distribution.
3169    
3170     2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
3171     unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
3172     where "ddd" means "one or more decimal digits".
3173    
3174     3. Fixed serious bug. If a pattern had a back reference, but the call to
3175     pcre_exec() didn't supply a large enough ovector to record the related
3176     identifying subpattern, the match always failed. PCRE now remembers the number
3177     of the largest back reference, and gets some temporary memory in which to save
3178     the offsets during matching if necessary, in order to ensure that
3179     backreferences always work.
3180    
3181     4. Increased the compatibility with Perl in a number of ways:
3182    
3183     (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
3184     to request this handling. The option can be set at compile or exec time.
3185    
3186     (b) $ matches before a terminating newline by default; an option
3187     PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
3188     mode). The option can be set at compile or exec time.
3189    
3190     (c) The handling of \ followed by a digit other than 0 is now supposed to be
3191     the same as Perl's. If the decimal number it represents is less than 10
3192     or there aren't that many previous left capturing parentheses, an octal
3193     escape is read. Inside a character class, it's always an octal escape,
3194     even if it is a single digit.
3195    
3196     (d) An escaped but undefined alphabetic character is taken as a literal,
3197     unless PCRE_EXTRA is set. Currently this just reserves the remaining
3198     escapes.
3199    
3200     (e) {0} is now permitted. (The previous item is removed from the compiled
3201     pattern).
3202    
3203     5. Changed all the names of code files so that the basic parts are no longer
3204     than 10 characters, and abolished the teeny "globals.c" file.
3205    
3206     6. Changed the handling of character classes; they are now done with a 32-byte
3207     bit map always.
3208    
3209     7. Added the -d and /D options to pcretest to make it possible to look at the
3210     internals of compilation without having to recompile pcre.
3211    
3212    
3213     Version 0.95 23-Sep-97
3214     ----------------------
3215    
3216     1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
3217     \x20 at the start of a run of normal characters. These were being treated as
3218     real characters, instead of the source characters being re-checked.
3219    
3220    
3221     Version 0.94 18-Sep-97
3222     ----------------------
3223    
3224     1. The functions are now thread-safe, with the caveat that the global variables
3225     containing pointers to malloc() and free() or alternative functions are the
3226     same for all threads.
3227    
3228     2. Get pcre_study() to generate a bitmap of initial characters for non-
3229     anchored patterns when this is possible, and use it if passed to pcre_exec().
3230    
3231    
3232     Version 0.93 15-Sep-97
3233     ----------------------
3234    
3235     1. /(b)|(:+)/ was computing an incorrect first character.
3236    
3237     2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
3238     but not actually doing anything yet.
3239    
3240     3. Treat "-" characters in classes that cannot be part of ranges as literals,
3241     as Perl does (e.g. [-az] or [az-]).
3242    
3243     4. Set the anchored flag if a branch starts with .* or .*? because that tests
3244     all possible positions.
3245    
3246     5. Split up into different modules to avoid including unneeded functions in a
3247     compiled binary. However, compile and exec are still in one module. The "study"
3248     function is split off.
3249    
3250     6. The character tables are now in a separate module whose source is generated
3251     by an auxiliary program - but can then be edited by hand if required. There are
3252     now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
3253     toupper() in the code.
3254    
3255     7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
3256     make them global. Abolish the function for setting them, as the caller can now
3257     set them directly.
3258    
3259    
3260     Version 0.92 11-Sep-97
3261     ----------------------
3262    
3263     1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
3264     (e.g. /a{1,3}/) was broken (I mis-optimized it).
3265    
3266     2. Caseless matching was not working in character classes if the characters in
3267     the pattern were in upper case.
3268    
3269     3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
3270    
3271     4. Make PCRE_ANCHORED public and accept as a compile option.
3272    
3273     5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
3274     PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
3275     pass them.
3276    
3277     6. Give an error if bad option bits passed at compile or run time.
3278    
3279     7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
3280     pcretest to cause it to pass that flag.
3281    
3282     8. Add pcre_info(), to get the number of identifying subpatterns, the stored
3283     options, and the first character, if set.
3284    
3285     9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
3286    
3287    
3288     Version 0.91 10-Sep-97
3289     ----------------------
3290    
3291     1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
3292     match the empty string as in /(a*)*/. It was looping and ultimately crashing.
3293    
3294     2. PCRE was looping on encountering an indefinitely repeated back reference to
3295     a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
3296     Perl does - treats the match as successful.
3297    
3298     ****

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