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Revision 345 - (hide annotations) (download)
Mon Apr 28 15:10:02 2008 UTC (5 years, 11 months ago) by ph10
File size: 155838 byte(s)
Tidies for the 7.7-RC1 distribution.

1 nigel 3 ChangeLog for PCRE
2     ------------------
3    
4 ph10 345 Version 7.7 28-Apr-08
5 ph10 321 ---------------------
6    
7     1. Applied Craig's patch to sort out a long long problem: "If we can't convert
8 ph10 345 a string to a long long, pretend we don't even have a long long." This is
9 ph10 321 done by checking for the strtoq, strtoll, and _strtoi64 functions.
10 ph10 345
11 ph10 322 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
12     pre-7.6 versions, which defined a global no_arg variable instead of putting
13 ph10 332 it in the RE class. (See also #8 below.)
14 ph10 345
15     3. Remove a line of dead code, identified by coverity and reported by Nuno
16     Lopes.
17    
18 ph10 324 4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
19 ph10 321
20 ph10 324 (1) The include/exclude patterns were being applied to the whole pathnames
21 ph10 345 of files, instead of just to the final components.
22    
23 ph10 324 (2) If there was more than one level of directory, the subdirectories were
24     skipped unless they satisfied the include/exclude conditions. This is
25     inconsistent with GNU grep (and could even be seen as contrary to the
26     pcregrep specification - which I improved to make it absolutely clear).
27     The action now is always to scan all levels of directory, and just
28     apply the include/exclude patterns to regular files.
29 ph10 345
30 ph10 325 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
31 ph10 345 --exclude_dir in the tests to avoid scanning .svn directories.
32    
33 ph10 326 6. Applied Craig's patch to the QuoteMeta function so that it escapes the
34 ph10 345 NUL character as backslash + 0 rather than backslash + NUL, because PCRE
35 ph10 326 doesn't support NULs in patterns.
36 ph10 345
37     7. Added some missing "const"s to declarations of static tables in
38     pcre_compile.c and pcre_dfa_exec.c.
39    
40 ph10 328 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
41 ph10 329 caused by fix #2 above. (Subsequently also a second patch to fix the
42 ph10 345 first patch. And a third patch - this was a messy problem.)
43 ph10 321
44 ph10 345 9. Applied Craig's patch to remove the use of push_back().
45    
46 ph10 332 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
47     matching function regexec().
48 ph10 345
49     11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
50     which, however, unlike Perl's \g{...}, are subroutine calls, not back
51 ph10 333 references. PCRE supports relative numbers with this syntax (I don't think
52     Oniguruma does).
53 ph10 345
54     12. Previously, a group with a zero repeat such as (...){0} was completely
55 ph10 335 omitted from the compiled regex. However, this means that if the group
56     was called as a subroutine from elsewhere in the pattern, things went wrong
57 ph10 345 (an internal error was given). Such groups are now left in the compiled
58     pattern, with a new opcode that causes them to be skipped at execution
59 ph10 335 time.
60 ph10 345
61 ph10 341 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
62     to the way PCRE behaves:
63 ph10 345
64 ph10 336 (a) A lone ] character is dis-allowed (Perl treats it as data).
65 ph10 345
66     (b) A back reference to an unmatched subpattern matches an empty string
67 ph10 336 (Perl fails the current match path).
68 ph10 345
69 ph10 341 (c) A data ] in a character class must be notated as \] because if the
70 ph10 345 first data character in a class is ], it defines an empty class. (In
71 ph10 341 Perl it is not possible to have an empty class.) The empty class []
72     never matches; it forces failure and is equivalent to (*FAIL) or (?!).
73     The negative empty class [^] matches any one character, independently
74     of the DOTALL setting.
75 ph10 345
76     14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
77 ph10 340 non-existent subpattern following a character class starting with ']' and
78     containing () gave an internal compiling error instead of "reference to
79     non-existent subpattern". Fortunately, when the pattern did exist, the
80 ph10 345 compiled code was correct. (When scanning forwards to check for the
81 ph10 340 existencd of the subpattern, it was treating the data ']' as terminating
82 ph10 345 the class, so got the count wrong. When actually compiling, the reference
83 ph10 340 was subsequently set up correctly.)
84 ph10 345
85 ph10 341 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
86 ph10 345 it was being rejected as not supported by pcre_dfa_exec(), even though
87     other assertions are supported. I have made pcre_dfa_exec() support
88     (*FAIL).
89    
90 ph10 342 16. The implementation of 13c above involved the invention of a new opcode,
91 ph10 345 OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
92     cannot be changed at match time, I realized I could make a small
93     improvement to matching performance by compiling OP_ALLANY instead of
94     OP_ANY for "." when DOTALL was set, and then removing the runtime tests
95     on the OP_ANY path.
96    
97     17. Compiling pcretest on Windows with readline support failed without the
98 ph10 343 following two fixes: (1) Make the unistd.h include conditional on
99 ph10 345 HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
100    
101 ph10 344 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
102 ph10 345 ncurses library to be included for pcretest when ReadLine support is
103     requested, but also to allow for it to be overridden. This patch came from
104     Daniel Bergström.
105 ph10 324
106 ph10 332
107 ph10 319 Version 7.6 28-Jan-08
108 ph10 300 ---------------------
109    
110 ph10 302 1. A character class containing a very large number of characters with
111     codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
112     overflow.
113 ph10 309
114     2. Patch to cut out the "long long" test in pcrecpp_unittest when
115     HAVE_LONG_LONG is not defined.
116    
117 ph10 303 3. Applied Christian Ehrlicher's patch to update the CMake build files to
118 ph10 304 bring them up to date and include new features. This patch includes:
119 ph10 309
120 ph10 304 - Fixed PH's badly added libz and libbz2 support.
121     - Fixed a problem with static linking.
122 ph10 312 - Added pcredemo. [But later removed - see 7 below.]
123 ph10 304 - Fixed dftables problem and added an option.
124     - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
125     HAVE_LONG_LONG.
126     - Added readline support for pcretest.
127 ph10 309 - Added an listing of the option settings after cmake has run.
128    
129 ph10 314 4. A user submitted a patch to Makefile that makes it easy to create
130     "pcre.dll" under mingw when using Configure/Make. I added stuff to
131     Makefile.am that cause it to include this special target, without
132     affecting anything else. Note that the same mingw target plus all
133     the other distribution libraries and programs are now supported
134     when configuring with CMake (see 6 below) instead of with
135     Configure/Make.
136 ph10 309
137 ph10 308 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
138     This is an attempt to solve the reported problem "pcrecpp::no_arg is not
139 ph10 309 exported in the Windows port". It has not yet been confirmed that the patch
140     solves the problem, but it does no harm.
141 ph10 313
142 ph10 311 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
143 ph10 319 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
144 ph10 314 with CMake, and also correct the comment about stack recursion.
145 ph10 313
146 ph10 312 7. Remove the automatic building of pcredemo from the ./configure system and
147 ph10 313 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
148     of a program that users should build themselves after PCRE is installed, so
149     building it automatically is not really right. What is more, it gave
150 ph10 312 trouble in some build environments.
151 ph10 300
152 ph10 319 8. Further tidies to CMakeLists.txt from Sheri and Christian.
153 ph10 308
154 ph10 319
155 ph10 298 Version 7.5 10-Jan-08
156 ph10 263 ---------------------
157    
158     1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
159     values in parens when parsing an RE using the C++ wrapper."
160 ph10 286
161 ph10 264 2. Negative specials like \S did not work in character classes in UTF-8 mode.
162     Characters greater than 255 were excluded from the class instead of being
163     included.
164 ph10 286
165     3. The same bug as (2) above applied to negated POSIX classes such as
166 ph10 265 [:^space:].
167 ph10 286
168 ph10 267 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
169     defined or documented. It seems to have been a typo for PCRE_STATIC, so
170 ph10 286 I have changed it.
171    
172 ph10 268 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
173 ph10 286 first named subpattern) and a construct such as (?&a) would reference the
174     first named subpattern whose name started with "a" (in other words, the
175 ph10 272 length check was missing). Both these problems are fixed. "Subpattern name
176     expected" is now given for (?&) (a zero-length name), and this patch also
177     makes it give the same error for \k'' (previously it complained that that
178     was a reference to a non-existent subpattern).
179 ph10 286
180 ph10 269 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
181 ph10 286 this is right because (?- can be followed by option settings as well as by
182 ph10 269 digits. I have, however, made the messages clearer.
183 ph10 286
184 ph10 270 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
185     than the number used in the conditional) now cause a compile-time error.
186     This is actually not compatible with Perl, which accepts such patterns, but
187     treats the conditional as always being FALSE (as PCRE used to), but it
188     seems to me that giving a diagnostic is better.
189 ph10 286
190 ph10 274 8. Change "alphameric" to the more common word "alphanumeric" in comments
191 ph10 275 and messages.
192 ph10 286
193     9. Fix two occurrences of "backslash" in comments that should have been
194     "backspace".
195    
196     10. Remove two redundant lines of code that can never be obeyed (their function
197     was moved elsewhere).
198    
199     11. The program that makes PCRE's Unicode character property table had a bug
200     which caused it to generate incorrect table entries for sequences of
201 ph10 277 characters that have the same character type, but are in different scripts.
202 ph10 286 It amalgamated them into a single range, with the script of the first of
203 ph10 277 them. In other words, some characters were in the wrong script. There were
204     thirteen such cases, affecting characters in the following ranges:
205 ph10 286
206 ph10 277 U+002b0 - U+002c1
207     U+0060c - U+0060d
208 ph10 286 U+0061e - U+00612
209 ph10 277 U+0064b - U+0065e
210     U+0074d - U+0076d
211     U+01800 - U+01805
212     U+01d00 - U+01d77
213     U+01d9b - U+01dbf
214     U+0200b - U+0200f
215     U+030fc - U+030fe
216     U+03260 - U+0327f
217     U+0fb46 - U+0fbb1
218     U+10450 - U+1049d
219 ph10 286
220 ph10 279 12. The -o option (show only the matching part of a line) for pcregrep was not
221     compatible with GNU grep in that, if there was more than one match in a
222     line, it showed only the first of them. It now behaves in the same way as
223     GNU grep.
224 ph10 286
225     13. If the -o and -v options were combined for pcregrep, it printed a blank
226     line for every non-matching line. GNU grep prints nothing, and pcregrep now
227     does the same. The return code can be used to tell if there were any
228     non-matching lines.
229    
230 ph10 289 14. Added --file-offsets and --line-offsets to pcregrep.
231    
232     15. The pattern (?=something)(?R) was not being diagnosed as a potentially
233 ph10 282 infinitely looping recursion. The bug was that positive lookaheads were not
234 ph10 286 being skipped when checking for a possible empty match (negative lookaheads
235     and both kinds of lookbehind were skipped).
236    
237 ph10 289 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
238 ph10 284 inclusion of <windows.h> to before rather than after the definition of
239     INVALID_FILE_ATTRIBUTES (patch from David Byron).
240 ph10 263
241 ph10 289 17. Specifying a possessive quantifier with a specific limit for a Unicode
242 ph10 286 character property caused pcre_compile() to compile bad code, which led at
243     runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
244     are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
245     caused the error; without that there was no problem.
246 ph10 263
247 ph10 289 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
248 ph10 286
249 ph10 289 19. Added --enable-pcretest-libreadline.
250 ph10 286
251 ph10 289 20. In pcrecpp.cc, the variable 'count' was incremented twice in
252 ph10 288 RE::GlobalReplace(). As a result, the number of replacements returned was
253 ph10 298 double what it should be. I removed one of the increments, but Craig sent a
254     later patch that removed the other one (the right fix) and added unit tests
255     that check the return values (which was not done before).
256 ph10 292
257 ph10 291 21. Several CMake things:
258 ph10 287
259 ph10 291 (1) Arranged that, when cmake is used on Unix, the libraries end up with
260 ph10 292 the names libpcre and libpcreposix, not just pcre and pcreposix.
261 ph10 288
262 ph10 292 (2) The above change means that pcretest and pcregrep are now correctly
263     linked with the newly-built libraries, not previously installed ones.
264 ph10 291
265 ph10 292 (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
266 ph10 298
267     22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
268     crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
269     UTF-8 newline character). The key issue is that the pattern starts .*;
270     this means that the match must be either at the beginning, or after a
271     newline. The bug was in the code for advancing after a failed match and
272     checking that the new position followed a newline. It was not taking
273 ph10 294 account of UTF-8 characters correctly.
274 ph10 298
275     23. PCRE was behaving differently from Perl in the way it recognized POSIX
276     character classes. PCRE was not treating the sequence [:...:] as a
277     character class unless the ... were all letters. Perl, however, seems to
278     allow any characters between [: and :], though of course it rejects as
279     unknown any "names" that contain non-letters, because all the known class
280     names consist only of letters. Thus, Perl gives an error for [[:1234:]],
281     for example, whereas PCRE did not - it did not recognize a POSIX character
282     class. This seemed a bit dangerous, so the code has been changed to be
283     closer to Perl. The behaviour is not identical to Perl, because PCRE will
284     diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
285     treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
286     Perl does, and where it didn't before.
287    
288 ph10 296 24. Rewrite so as to remove the single use of %n from pcregrep because in some
289     Windows environments %n is disabled by default.
290 ph10 292
291    
292 ph10 260 Version 7.4 21-Sep-07
293 ph10 230 ---------------------
294    
295     1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
296 ph10 231 means that a class such as [\s] counted as "explicit reference to CR or
297     LF". That isn't really right - the whole point of the change was to try to
298     help when there was an actual mention of one of the two characters. So now
299     the change happens only if \r or \n (or a literal CR or LF) character is
300 ph10 230 encountered.
301 ph10 231
302     2. The 32-bit options word was also used for 6 internal flags, but the numbers
303     of both had grown to the point where there were only 3 bits left.
304     Fortunately, there was spare space in the data structure, and so I have
305     moved the internal flags into a new 16-bit field to free up more option
306 ph10 230 bits.
307 ph10 231
308     3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
309     but did not set the internal JCHANGED flag - either of these is enough to
310     control the way the "get" function works - but the PCRE_INFO_JCHANGED
311     facility is supposed to tell if (?J) was ever used, so now (?J) at the
312 ph10 230 start sets both bits.
313    
314 ph10 231 4. Added options (at build time, compile time, exec time) to change \R from
315     matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
316 ph10 230
317 ph10 243 5. doc/pcresyntax.html was missing from the distribution.
318    
319     6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
320 ph10 233 compatibility, even though it is no longer used.
321 ph10 243
322     7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
323 ph10 254 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
324 ph10 259 windows.h file is present (where different names are used). [This was
325 ph10 257 reversed later after testing - see 16 below.]
326 ph10 243
327     8. Changed all #include <config.h> to #include "config.h". There were also
328 ph10 236 some further <pcre.h> cases that I changed to "pcre.h".
329 ph10 243
330 ph10 239 9. When pcregrep was used with the --colour option, it missed the line ending
331 ph10 243 sequence off the lines that it output.
332    
333     10. It was pointed out to me that arrays of string pointers cause lots of
334     relocations when a shared library is dynamically loaded. A technique of
335     using a single long string with a table of offsets can drastically reduce
336     these. I have refactored PCRE in four places to do this. The result is
337 ph10 240 dramatic:
338 ph10 243
339 ph10 240 Originally: 290
340     After changing UCP table: 187
341 ph10 243 After changing error message table: 43
342 ph10 240 After changing table of "verbs" 36
343     After changing table of Posix names 22
344 ph10 243
345 ph10 240 Thanks to the folks working on Gregex for glib for this insight.
346 ph10 247
347 ph10 244 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
348 ph10 247 unicode-properties was also set.
349    
350 ph10 248 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
351 ph10 231
352 ph10 253 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
353     checked only for CRLF.
354 ph10 233
355 ph10 259 14. Added casts to pcretest.c to avoid compiler warnings.
356    
357 ph10 256 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
358 ph10 253
359 ph10 257 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
360 ph10 259 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
361     entirely. This removes changes made in 7 above.
362 ph10 256
363 ph10 261 17. The CMake files have been updated, and there is now more information about
364     building with CMake in the NON-UNIX-USE document.
365 ph10 257
366 ph10 261
367 ph10 228 Version 7.3 28-Aug-07
368 ph10 157 ---------------------
369    
370 ph10 189 1. In the rejigging of the build system that eventually resulted in 7.1, the
371     line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
372     brackets there is not right, since it causes compilers to look for an
373     installed pcre.h, not the version that is in the source that is being
374     compiled (which of course may be different). I have changed it back to:
375 ph10 197
376 ph10 189 #include "pcre.h"
377 ph10 197
378     I have a vague recollection that the change was concerned with compiling in
379     different directories, but in the new build system, that is taken care of
380     by the VPATH setting the Makefile.
381    
382 ph10 190 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
383     when the subject happened to end in the byte 0x85 (e.g. if the last
384     character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
385     characters but of course it shouldn't be taken as a newline when it is part
386     of another character. The bug was that, for an unlimited repeat of . in
387     not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
388     characters when looking for a newline.
389 ph10 197
390     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
391    
392     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
393     in debug output.
394    
395 ph10 201 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
396     long printing in the pcrecpp unittest when running under MinGW.
397 ph10 189
398 ph10 197 6. ESC_K was left out of the EBCDIC table.
399 ph10 189
400 ph10 197 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
401     parentheses; I made it 1000, which seemed large enough. Unfortunately, the
402     limit also applies to "virtual nesting" when a pattern is recursive, and in
403     this case 1000 isn't so big. I have been able to remove this limit at the
404     expense of backing off one optimization in certain circumstances. Normally,
405     when pcre_exec() would call its internal match() function recursively and
406     immediately return the result unconditionally, it uses a "tail recursion"
407     feature to save stack. However, when a subpattern that can match an empty
408     string has an unlimited repetition quantifier, it no longer makes this
409     optimization. That gives it a stack frame in which to save the data for
410     checking that an empty string has been matched. Previously this was taken
411     from the 1000-entry workspace that had been reserved. So now there is no
412     explicit limit, but more stack is used.
413 ph10 189
414 ph10 200 8. Applied Daniel's patches to solve problems with the import/export magic
415     syntax that is required for Windows, and which was going wrong for the
416     pcreposix and pcrecpp parts of the library. These were overlooked when this
417     problem was solved for the main library.
418 ph10 197
419 ph10 202 9. There were some crude static tests to avoid integer overflow when computing
420     the size of patterns that contain repeated groups with explicit upper
421     limits. As the maximum quantifier is 65535, the maximum group length was
422     set at 30,000 so that the product of these two numbers did not overflow a
423     32-bit integer. However, it turns out that people want to use groups that
424     are longer than 30,000 bytes (though not repeat them that many times).
425     Change 7.0/17 (the refactoring of the way the pattern size is computed) has
426     made it possible to implement the integer overflow checks in a much more
427     dynamic way, which I have now done. The artificial limitation on group
428     length has been removed - we now have only the limit on the total length of
429     the compiled pattern, which depends on the LINK_SIZE setting.
430 ph10 208
431     10. Fixed a bug in the documentation for get/copy named substring when
432     duplicate names are permitted. If none of the named substrings are set, the
433     functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
434     empty string.
435    
436     11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
437     instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
438     because the ] is interpreted as the first data character and the
439     terminating ] is not found. PCRE has been made compatible with Perl in this
440     regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
441     cause memory overwriting.
442    
443 ph10 206 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
444     string has been matched (to stop an infinite loop). It was not recognizing
445 ph10 208 a conditional subpattern that could match an empty string if that
446 ph10 206 subpattern was within another subpattern. For example, it looped when
447 ph10 208 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
448 ph10 206 condition was not nested. This bug has been fixed.
449 ph10 208
450 ph10 207 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
451     past the start of the subject in the presence of bytes with the top bit
452     set, for example "\x8aBCD".
453 ph10 211
454 ph10 210 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
455     (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
456 ph10 200
457 ph10 211 14. Optimized (?!) to (*FAIL).
458 ph10 202
459 ph10 212 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
460     This restricts code points to be within the range 0 to 0x10FFFF, excluding
461     the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
462     full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
463     does: it's just the validity check that is more restrictive.
464 ph10 220
465     16. Inserted checks for integer overflows during escape sequence (backslash)
466     processing, and also fixed erroneous offset values for syntax errors during
467     backslash processing.
468    
469 ph10 214 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
470 ph10 220 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
471    
472 ph10 215 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
473     caused an overrun.
474 ph10 220
475     19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
476     something other than just ASCII characters) inside a group that had an
477     unlimited repeat caused a loop at compile time (while checking to see
478     whether the group could match an empty string).
479    
480 ph10 217 20. Debugging a pattern containing \p or \P could cause a crash. For example,
481     [\P{Any}] did so. (Error in the code for printing property names.)
482 ph10 210
483 ph10 220 21. An orphan \E inside a character class could cause a crash.
484    
485     22. A repeated capturing bracket such as (A)? could cause a wild memory
486 ph10 218 reference during compilation.
487 ph10 220
488     23. There are several functions in pcre_compile() that scan along a compiled
489     expression for various reasons (e.g. to see if it's fixed length for look
490 ph10 218 behind). There were bugs in these functions when a repeated \p or \P was
491 ph10 220 present in the pattern. These operators have additional parameters compared
492     with \d, etc, and these were not being taken into account when moving along
493 ph10 218 the compiled data. Specifically:
494 ph10 220
495     (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
496     length.
497    
498     (b) An item such as \pL+ within a repeated group could cause crashes or
499 ph10 218 loops.
500 ph10 220
501 ph10 218 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
502 ph10 220 "reference to non-existent subpattern" error.
503    
504 ph10 221 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
505    
506 ph10 219 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
507 ph10 220 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
508 ph10 211
509 ph10 222 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
510 ph10 218
511 ph10 227 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
512 ph10 223 character were causing crashes (broken optimization).
513 ph10 227
514 ph10 224 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
515 ph10 227 \p or \P) caused a compile-time loop.
516    
517 ph10 226 28. More problems have arisen in unanchored patterns when CRLF is a valid line
518     break. For example, the unstudied pattern [\r\n]A does not match the string
519     "\r\nA" because change 7.0/46 below moves the current point on by two
520     characters after failing to match at the start. However, the pattern \nA
521 ph10 227 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
522     the same is true. There doesn't seem any very clean way out of this, but
523     what I have chosen to do makes the common cases work: PCRE now takes note
524     of whether there can be an explicit match for \r or \n anywhere in the
525     pattern, and if so, 7.0/46 no longer applies. As part of this change,
526     there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
527     pattern has explicit CR or LF references.
528 ph10 222
529 ph10 227 29. Added (*CR) etc for changing newline setting at start of pattern.
530 ph10 223
531 ph10 227
532 ph10 189 Version 7.2 19-Jun-07
533     ---------------------
534    
535 ph10 157 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
536     which is apparently normally available under Windows.
537 ph10 159
538     2. Re-jig the pcregrep tests with different newline settings in an attempt
539     to make them independent of the local environment's newline setting.
540 ph10 157
541 ph10 160 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
542 ph10 165
543 ph10 161 4. Some of the "internals" tests were previously cut out when the link size
544     was not 2, because the output contained actual offsets. The recent new
545 ph10 165 "Z" feature of pcretest means that these can be cut out, making the tests
546     usable with all link sizes.
547    
548 ph10 164 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
549     stack recursion. This gives a massive performance boost under BSD, but just
550 ph10 165 a small improvement under Linux. However, it saves one field in the frame
551 ph10 164 in all cases.
552 ph10 172
553 ph10 166 6. Added more features from the forthcoming Perl 5.10:
554 ph10 172
555 ph10 166 (a) (?-n) (where n is a string of digits) is a relative subroutine or
556     recursion call. It refers to the nth most recently opened parentheses.
557 ph10 172
558 ph10 166 (b) (?+n) is also a relative subroutine call; it refers to the nth next
559 ph10 172 to be opened parentheses.
560    
561     (c) Conditions that refer to capturing parentheses can be specified
562 ph10 167 relatively, for example, (?(-2)... or (?(+3)...
563 ph10 172
564 ph10 168 (d) \K resets the start of the current match so that everything before
565 ph10 172 is not part of it.
566    
567 ph10 171 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
568 ph10 172
569 ph10 171 (f) \g{name} is another synonym - part of Perl 5.10's unification of
570 ph10 172 reference syntax.
571 ph10 182
572 ph10 175 (g) (?| introduces a group in which the numbering of parentheses in each
573 ph10 182 alternative starts with the same number.
574 ph10 172
575 ph10 182 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
576    
577 ph10 172 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
578     PCRE_INFO_JCHANGED.
579    
580     8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
581     terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
582 ph10 170 for detecting groups that can match an empty string.
583 ph10 159
584 ph10 172 9. A pattern with a very large number of alternatives (more than several
585     hundred) was running out of internal workspace during the pre-compile
586     phase, where pcre_compile() figures out how much memory will be needed. A
587     bit of new cunning has reduced the workspace needed for groups with
588     alternatives. The 1000-alternative test pattern now uses 12 bytes of
589     workspace instead of running out of the 4096 that are available.
590 ph10 182
591 ph10 176 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
592 ph10 172
593 ph10 179 11. Applied patch from Google to remove an optimization that didn't quite work.
594     The report of the bug said:
595 ph10 182
596 ph10 179 pcrecpp::RE("a*").FullMatch("aaa") matches, while
597     pcrecpp::RE("a*?").FullMatch("aaa") does not, and
598 ph10 182 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
599 ph10 185
600 ph10 184 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
601 ph10 185 it matched the wrong number of bytes.
602 ph10 172
603 ph10 179
604 ph10 155 Version 7.1 24-Apr-07
605 ph10 98 ---------------------
606    
607 ph10 111 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
608 ph10 122 that is more "standard", making use of automake and other Autotools. There
609 ph10 99 is some re-arrangement of the files and adjustment of comments consequent
610     on this.
611 ph10 111
612     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
613     for recursive directory scanning broke on some systems because the files
614     are not scanned in any specific order and on different systems the order
615     was different. A call to "sort" has been inserted into RunGrepTest for the
616     approprate test as a short-term fix. In the longer term there may be an
617 ph10 100 alternative.
618 ph10 111
619 ph10 100 3. I had an email from Eric Raymond about problems translating some of PCRE's
620 ph10 111 man pages to HTML (despite the fact that I distribute HTML pages, some
621     people do their own conversions for various reasons). The problems
622     concerned the use of low-level troff macros .br and .in. I have therefore
623     removed all such uses from the man pages (some were redundant, some could
624 ph10 113 be replaced by .nf/.fi pairs). The 132html script that I use to generate
625     HTML has been updated to handle .nf/.fi and to complain if it encounters
626     .br or .in.
627 ph10 111
628 ph10 100 4. Updated comments in configure.ac that get placed in config.h.in and also
629 ph10 123 arranged for config.h to be included in the distribution, with the name
630 ph10 111 config.h.generic, for the benefit of those who have to compile without
631     Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
632    
633     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
634     Weber: (1) pcre_internal.h was missing some function renames; (2) updated
635 ph10 127 makevp.bat for the current PCRE, using the additional files
636 ph10 135 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
637 ph10 111
638     6. A Windows user reported a minor discrepancy with test 2, which turned out
639     to be caused by a trailing space on an input line that had got lost in his
640 ph10 102 copy. The trailing space was an accident, so I've just removed it.
641 ph10 111
642 ph10 104 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
643 ph10 111 that is needed.
644    
645 ph10 105 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
646     as "const" (a) because they are and (b) because it helps the PHP
647     maintainers who have recently made a script to detect big data structures
648 ph10 111 in the php code that should be moved to the .rodata section. I remembered
649     to update Builducptable as well, so it won't revert if ucptable.h is ever
650 ph10 105 re-created.
651 ph10 111
652     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
653 ph10 107 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
654 ph10 111 order to be able to cut out the UTF-8 tables in the latter when UTF-8
655     support is not required. This saves 1.5-2K of code, which is important in
656 ph10 107 some applications.
657 ph10 111
658 ph10 110 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
659 ph10 111 so as not to refer to the tables, even though these functions will never be
660     called when UTF-8 support is disabled. Otherwise there are problems with a
661     shared library.
662    
663 ph10 118 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
664    
665     (a) It was defining its arguments as char * instead of void *.
666    
667 ph10 123 (b) It was assuming that all moves were upwards in memory; this was true
668     a long time ago when I wrote it, but is no longer the case.
669    
670 ph10 118 The emulated memove() is provided for those environments that have neither
671 ph10 123 memmove() nor bcopy(). I didn't think anyone used it these days, but that
672 ph10 118 is clearly not the case, as these two bugs were recently reported.
673 ph10 123
674 ph10 111 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
675 ph10 123 and Detrail to create the HTML documentation, the .txt form of the man
676     pages, and it removes trailing spaces from listed files. It also creates
677     pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
678     case, it wraps all the #defines with #ifndefs. This script should be run
679 ph10 111 before "make dist".
680 ph10 123
681 ph10 115 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
682     with Unicode property support.
683 ph10 123
684     (a) For a maximizing quantifier, if the two different cases of the
685     character were of different lengths in their UTF-8 codings (there are
686     some cases like this - I found 11), and the matching function had to
687 ph10 115 back up over a mixture of the two cases, it incorrectly assumed they
688     were both the same length.
689 ph10 123
690     (b) When PCRE was configured to use the heap rather than the stack for
691     recursion during matching, it was not correctly preserving the data for
692     the other case of a UTF-8 character when checking ahead for a match
693     while processing a minimizing repeat. If the check also involved
694 ph10 115 matching a wide character, but failed, corruption could cause an
695     erroneous result when trying to check for a repeat of the original
696     character.
697 ph10 123
698 ph10 116 13. Some tidying changes to the testing mechanism:
699 ph10 98
700 ph10 116 (a) The RunTest script now detects the internal link size and whether there
701     is UTF-8 and UCP support by running ./pcretest -C instead of relying on
702 ph10 123 values substituted by "configure". (The RunGrepTest script already did
703     this for UTF-8.) The configure.ac script no longer substitutes the
704     relevant variables.
705    
706 ph10 116 (b) The debugging options /B and /D in pcretest show the compiled bytecode
707     with length and offset values. This means that the output is different
708     for different internal link sizes. Test 2 is skipped for link sizes
709     other than 2 because of this, bypassing the problem. Unfortunately,
710     there was also a test in test 3 (the locale tests) that used /B and
711 ph10 123 failed for link sizes other than 2. Rather than cut the whole test out,
712     I have added a new /Z option to pcretest that replaces the length and
713     offset values with spaces. This is now used to make test 3 independent
714 ph10 122 of link size. (Test 2 will be tidied up later.)
715 ph10 123
716     14. If erroroffset was passed as NULL to pcre_compile, it provoked a
717 ph10 122 segmentation fault instead of returning the appropriate error message.
718 ph10 134
719 ph10 131 15. In multiline mode when the newline sequence was set to "any", the pattern
720 ph10 134 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
721     This doesn't seem right; it now treats the CRLF combination as the line
722     ending, and so does not match in that case. It's only a pattern such as ^$
723     that would hit this one: something like ^ABC$ would have failed after \r
724     and then tried again after \r\n.
725    
726 ph10 131 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
727 ph10 134 in an attempt to make files that differ only in their line terminators
728     compare equal. This works on Linux.
729 ph10 142
730 ph10 141 17. Under certain error circumstances pcregrep might try to free random memory
731     as it exited. This is now fixed, thanks to valgrind.
732 ph10 142
733 ph10 141 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
734 ph10 142 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
735     was because its rules for how to advance for /g after matching an empty
736 ph10 143 string at the end of a line did not allow for this case. They now check for
737     it specially.
738 ph10 150
739     20. pcretest is supposed to handle patterns and data of any length, by
740     extending its buffers when necessary. It was getting this wrong when the
741 ph10 147 buffer for a data line had to be extended.
742 ph10 150
743 ph10 149 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
744 ph10 150 CRLF as a newline sequence.
745 ph10 152
746 ph10 151 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
747 ph10 152 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
748     I have nevertheless tidied it up.
749 ph10 111
750 ph10 152 23. Added some casts to kill warnings from HP-UX ia64 compiler.
751 ph10 123
752 ph10 153 24. Added a man page for pcre-config.
753 ph10 152
754 ph10 153
755 nigel 93 Version 7.0 19-Dec-06
756     ---------------------
757    
758     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
759     moving to gcc 4.1.1.
760    
761     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
762     sys/time.h, which is documented as needed for this function. It doesn't
763     seem to matter on Linux, but it showed up on some releases of OS X.
764    
765     3. It seems that there are systems where bytes whose values are greater than
766     127 match isprint() in the "C" locale. The "C" locale should be the
767     default when a C program starts up. In most systems, only ASCII printing
768     characters match isprint(). This difference caused the output from pcretest
769     to vary, making some of the tests fail. I have changed pcretest so that:
770    
771     (a) When it is outputting text in the compiled version of a pattern, bytes
772     other than 32-126 are always shown as hex escapes.
773    
774     (b) When it is outputting text that is a matched part of a subject string,
775     it does the same, unless a different locale has been set for the match
776     (using the /L modifier). In this case, it uses isprint() to decide.
777    
778     4. Fixed a major bug that caused incorrect computation of the amount of memory
779     required for a compiled pattern when options that changed within the
780     pattern affected the logic of the preliminary scan that determines the
781     length. The relevant options are -x, and -i in UTF-8 mode. The result was
782     that the computed length was too small. The symptoms of this bug were
783     either the PCRE error "internal error: code overflow" from pcre_compile(),
784     or a glibc crash with a message such as "pcretest: free(): invalid next
785     size (fast)". Examples of patterns that provoked this bug (shown in
786     pcretest format) are:
787    
788     /(?-x: )/x
789     /(?x)(?-x: \s*#\s*)/
790     /((?i)[\x{c0}])/8
791     /(?i:[\x{c0}])/8
792    
793     HOWEVER: Change 17 below makes this fix obsolete as the memory computation
794     is now done differently.
795    
796     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
797     wrapper classes; (b) implement a new function in the C++ scanner that is
798     more efficient than the old way of doing things because it avoids levels of
799     recursion in the regex matching; (c) add a paragraph to the documentation
800     for the FullMatch() function.
801    
802     6. The escape sequence \n was being treated as whatever was defined as
803     "newline". Not only was this contrary to the documentation, which states
804     that \n is character 10 (hex 0A), but it also went horribly wrong when
805     "newline" was defined as CRLF. This has been fixed.
806    
807     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
808     was being set to -1 for the "end of line" case (supposedly a value that no
809     character can have). Though this value is never used (the check for end of
810     line is "zero bytes in current character"), it caused compiler complaints.
811     I've changed it to 0xffffffff.
812    
813     8. In pcre_version.c, the version string was being built by a sequence of
814     C macros that, in the event of PCRE_PRERELEASE being defined as an empty
815     string (as it is for production releases) called a macro with an empty
816     argument. The C standard says the result of this is undefined. The gcc
817     compiler treats it as an empty string (which was what was wanted) but it is
818     reported that Visual C gives an error. The source has been hacked around to
819     avoid this problem.
820    
821     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
822     builds of pcretest, and changed the call to _setmode() to use _O_BINARY
823     instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
824     of them did).
825    
826     10. Originally, pcretest opened its input and output without "b"; then I was
827     told that "b" was needed in some environments, so it was added for release
828     5.0 to both the input and output. (It makes no difference on Unix-like
829     systems.) Later I was told that it is wrong for the input on Windows. I've
830     now abstracted the modes into two macros, to make it easier to fiddle with
831     them, and removed "b" from the input mode under Windows.
832    
833     11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
834    
835     12. Added -help and --help to pcretest as an official way of being reminded
836     of the options.
837    
838     13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
839     and pcrecpp.cc because they annoy compilers at high warning levels.
840    
841     14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
842    
843     15. Fixed an occurrence of == in configure.ac that should have been = (shell
844     scripts are not C programs :-) and which was not noticed because it works
845     on Linux.
846    
847     16. pcretest is supposed to handle any length of pattern and data line (as one
848     line or as a continued sequence of lines) by extending its input buffer if
849     necessary. This feature was broken for very long pattern lines, leading to
850     a string of junk being passed to pcre_compile() if the pattern was longer
851     than about 50K.
852    
853     17. I have done a major re-factoring of the way pcre_compile() computes the
854     amount of memory needed for a compiled pattern. Previously, there was code
855     that made a preliminary scan of the pattern in order to do this. That was
856     OK when PCRE was new, but as the facilities have expanded, it has become
857     harder and harder to keep it in step with the real compile phase, and there
858     have been a number of bugs (see for example, 4 above). I have now found a
859     cunning way of running the real compile function in a "fake" mode that
860     enables it to compute how much memory it would need, while actually only
861     ever using a few hundred bytes of working memory and without too many
862     tests of the mode. This should make future maintenance and development
863     easier. A side effect of this work is that the limit of 200 on the nesting
864     depth of parentheses has been removed (though this was never a serious
865     limitation, I suspect). However, there is a downside: pcre_compile() now
866     runs more slowly than before (30% or more, depending on the pattern). I
867     hope this isn't a big issue. There is no effect on runtime performance.
868    
869     18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
870     newline (only possible for the last line of a file) and it was a
871     pattern that set a locale (followed by /Lsomething), pcretest crashed.
872    
873     19. Added additional timing features to pcretest. (1) The -tm option now times
874     matching only, not compiling. (2) Both -t and -tm can be followed, as a
875     separate command line item, by a number that specifies the number of
876     repeats to use when timing. The default is 50000; this gives better
877     precision, but takes uncomfortably long for very large patterns.
878    
879     20. Extended pcre_study() to be more clever in cases where a branch of a
880     subpattern has no definite first character. For example, (a*|b*)[cd] would
881     previously give no result from pcre_study(). Now it recognizes that the
882     first character must be a, b, c, or d.
883    
884     21. There was an incorrect error "recursive call could loop indefinitely" if
885     a subpattern (or the entire pattern) that was being tested for matching an
886     empty string contained only one non-empty item after a nested subpattern.
887     For example, the pattern (?>\x{100}*)\d(?R) provoked this error
888     incorrectly, because the \d was being skipped in the check.
889    
890     22. The pcretest program now has a new pattern option /B and a command line
891     option -b, which is equivalent to adding /B to every pattern. This causes
892     it to show the compiled bytecode, without the additional information that
893     -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
894     is the same as /B/I).
895    
896     23. A new optimization is now able automatically to treat some sequences such
897     as a*b as a*+b. More specifically, if something simple (such as a character
898     or a simple class like \d) has an unlimited quantifier, and is followed by
899     something that cannot possibly match the quantified thing, the quantifier
900     is automatically "possessified".
901    
902     24. A recursive reference to a subpattern whose number was greater than 39
903     went wrong under certain circumstances in UTF-8 mode. This bug could also
904     have affected the operation of pcre_study().
905    
906     25. Realized that a little bit of performance could be had by replacing
907     (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
908    
909     26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
910    
911     27. Possessive quantifiers such as a++ were previously implemented by turning
912     them into atomic groups such as ($>a+). Now they have their own opcodes,
913     which improves performance. This includes the automatically created ones
914     from 23 above.
915    
916     28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
917     lookahead was broken if it was not anchored. PCRE was mistakenly expecting
918     the first matched character to be a colon. This applied both to named and
919     numbered groups.
920    
921     29. The ucpinternal.h header file was missing its idempotency #ifdef.
922    
923     30. I was sent a "project" file called libpcre.a.dev which I understand makes
924     building PCRE on Windows easier, so I have included it in the distribution.
925    
926     31. There is now a check in pcretest against a ridiculously large number being
927     returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
928     loop, the loop is abandoned.
929    
930     32. Forward references to subpatterns in conditions such as (?(2)...) where
931     subpattern 2 is defined later cause pcre_compile() to search forwards in
932     the pattern for the relevant set of parentheses. This search went wrong
933     when there were unescaped parentheses in a character class, parentheses
934     escaped with \Q...\E, or parentheses in a #-comment in /x mode.
935    
936     33. "Subroutine" calls and backreferences were previously restricted to
937     referencing subpatterns earlier in the regex. This restriction has now
938     been removed.
939    
940     34. Added a number of extra features that are going to be in Perl 5.10. On the
941     whole, these are just syntactic alternatives for features that PCRE had
942     previously implemented using the Python syntax or my own invention. The
943     other formats are all retained for compatibility.
944    
945     (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
946     as (?P<name>...). The new forms, as well as being in Perl 5.10, are
947     also .NET compatible.
948    
949     (b) A recursion or subroutine call to a named group can now be defined as
950     (?&name) as well as (?P>name).
951    
952     (c) A backreference to a named group can now be defined as \k<name> or
953     \k'name' as well as (?P=name). The new forms, as well as being in Perl
954     5.10, are also .NET compatible.
955    
956     (d) A conditional reference to a named group can now use the syntax
957     (?(<name>) or (?('name') as well as (?(name).
958    
959     (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
960     groups (named and numbered) that are never evaluated inline, but can be
961     called as "subroutines" from elsewhere. In effect, the DEFINE condition
962     is always false. There may be only one alternative in such a group.
963    
964     (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
965     as the simple (?(R). The condition is true only if the most recent
966     recursion is that of the given number or name. It does not search out
967     through the entire recursion stack.
968    
969     (g) The escape \gN or \g{N} has been added, where N is a positive or
970     negative number, specifying an absolute or relative reference.
971    
972     35. Tidied to get rid of some further signed/unsigned compiler warnings and
973     some "unreachable code" warnings.
974    
975     36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
976     things, this adds five new scripts.
977    
978     37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
979     There were also incompatibilities regarding the handling of \Q..\E inside
980     character classes, for example with patterns like [\Qa\E-\Qz\E] where the
981     hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
982    
983     38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
984     matches an empty string, and forcibly breaks the loop. There were bugs in
985     this code in non-simple cases. For a pattern such as ^(a()*)* matched
986     against aaaa the result was just "a" rather than "aaaa", for example. Two
987     separate and independent bugs (that affected different cases) have been
988     fixed.
989    
990     39. Refactored the code to abolish the use of different opcodes for small
991     capturing bracket numbers. This is a tidy that I avoided doing when I
992     removed the limit on the number of capturing brackets for 3.5 back in 2001.
993     The new approach is not only tidier, it makes it possible to reduce the
994     memory needed to fix the previous bug (38).
995    
996     40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
997     sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
998     processing dot, circumflex, or dollar metacharacters, or #-comments in /x
999     mode.
1000    
1001     41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
1002     report.
1003    
1004     42. Applied patch, originally from Ari Pollak, modified by Google, to allow
1005     copy construction and assignment in the C++ wrapper.
1006    
1007     43. Updated pcregrep to support "--newline=any". In the process, I fixed a
1008     couple of bugs that could have given wrong results in the "--newline=crlf"
1009     case.
1010    
1011     44. Added a number of casts and did some reorganization of signed/unsigned int
1012     variables following suggestions from Dair Grant. Also renamed the variable
1013     "this" as "item" because it is a C++ keyword.
1014    
1015     45. Arranged for dftables to add
1016    
1017     #include "pcre_internal.h"
1018    
1019     to pcre_chartables.c because without it, gcc 4.x may remove the array
1020     definition from the final binary if PCRE is built into a static library and
1021     dead code stripping is activated.
1022    
1023     46. For an unanchored pattern, if a match attempt fails at the start of a
1024     newline sequence, and the newline setting is CRLF or ANY, and the next two
1025     characters are CRLF, advance by two characters instead of one.
1026    
1027    
1028 nigel 91 Version 6.7 04-Jul-06
1029     ---------------------
1030    
1031     1. In order to handle tests when input lines are enormously long, pcretest has
1032     been re-factored so that it automatically extends its buffers when
1033     necessary. The code is crude, but this _is_ just a test program. The
1034     default size has been increased from 32K to 50K.
1035    
1036     2. The code in pcre_study() was using the value of the re argument before
1037     testing it for NULL. (Of course, in any sensible call of the function, it
1038     won't be NULL.)
1039    
1040     3. The memmove() emulation function in pcre_internal.h, which is used on
1041     systems that lack both memmove() and bcopy() - that is, hardly ever -
1042     was missing a "static" storage class specifier.
1043    
1044     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
1045     containing an extended class (one that cannot be represented by a bitmap
1046     because it contains high-valued characters or Unicode property items, e.g.
1047     [\pZ]). Almost always one would set UTF-8 mode when processing such a
1048     pattern, but PCRE should not loop if you do not (it no longer does).
1049     [Detail: two cases were found: (a) a repeated subpattern containing an
1050     extended class; (b) a recursive reference to a subpattern that followed a
1051     previous extended class. It wasn't skipping over the extended class
1052     correctly when UTF-8 mode was not set.]
1053    
1054     5. A negated single-character class was not being recognized as fixed-length
1055     in lookbehind assertions such as (?<=[^f]), leading to an incorrect
1056     compile error "lookbehind assertion is not fixed length".
1057    
1058     6. The RunPerlTest auxiliary script was showing an unexpected difference
1059     between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
1060     write a Perl script that can interpret lines of an input file either as
1061     byte characters or as UTF-8, which is what "perltest" was being required to
1062     do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
1063     can't do is switch easily at run time between having the "use utf8;" pragma
1064     or not. In the end, I fudged it by using the RunPerlTest script to insert
1065     "use utf8;" explicitly for the UTF-8 tests.
1066    
1067     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
1068     the end of the subject string, contrary to the documentation and to what
1069     Perl does. This was true of both matching functions. Now it matches only at
1070     the start of the subject and immediately after *internal* newlines.
1071    
1072     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
1073     a pointer to an int instead of a pointer to an unsigned long int. This
1074     caused problems on 64-bit systems.
1075    
1076     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
1077     instance of the 'standard' template library not being so standard".
1078    
1079     10. There was no check on the number of named subpatterns nor the maximum
1080     length of a subpattern name. The product of these values is used to compute
1081     the size of the memory block for a compiled pattern. By supplying a very
1082     long subpattern name and a large number of named subpatterns, the size
1083     computation could be caused to overflow. This is now prevented by limiting
1084     the length of names to 32 characters, and the number of named subpatterns
1085     to 10,000.
1086    
1087     11. Subpatterns that are repeated with specific counts have to be replicated in
1088     the compiled pattern. The size of memory for this was computed from the
1089     length of the subpattern and the repeat count. The latter is limited to
1090     65535, but there was no limit on the former, meaning that integer overflow
1091     could in principle occur. The compiled length of a repeated subpattern is
1092     now limited to 30,000 bytes in order to prevent this.
1093    
1094     12. Added the optional facility to have named substrings with the same name.
1095    
1096     13. Added the ability to use a named substring as a condition, using the
1097     Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
1098     are numbers (not recommended). Forward references are permitted.
1099    
1100     14. Added forward references in named backreferences (if you see what I mean).
1101    
1102     15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
1103     pattern could run off the end of the subject. For example, the pattern
1104     "(?s)(.{1,5})"8 did this with the subject "ab".
1105    
1106     16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
1107     PCRE_CASELESS was set when matching characters that were quantified with ?
1108     or *.
1109    
1110     17. A character class other than a single negated character that had a minimum
1111     but no maximum quantifier - for example [ab]{6,} - was not handled
1112     correctly by pce_dfa_exec(). It would match only one character.
1113    
1114     18. A valid (though odd) pattern that looked like a POSIX character
1115     class but used an invalid character after [ (for example [[,abc,]]) caused
1116     pcre_compile() to give the error "Failed: internal error: code overflow" or
1117     in some cases to crash with a glibc free() error. This could even happen if
1118     the pattern terminated after [[ but there just happened to be a sequence of
1119     letters, a binary zero, and a closing ] in the memory that followed.
1120    
1121     19. Perl's treatment of octal escapes in the range \400 to \777 has changed
1122     over the years. Originally (before any Unicode support), just the bottom 8
1123     bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1124     output from "man perlunicode" includes this:
1125    
1126     The regular expression compiler produces polymorphic opcodes. That
1127     is, the pattern adapts to the data and automatically switches to
1128     the Unicode character scheme when presented with Unicode data--or
1129     instead uses a traditional byte scheme when presented with byte
1130     data.
1131    
1132     Sadly, a wide octal escape does not cause a switch, and in a string with
1133     no other multibyte characters, these octal escapes are treated as before.
1134     Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
1135     /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1136     Unicode string.
1137    
1138     I have not perpetrated such confusion in PCRE. Up till now, it took just
1139     the bottom 8 bits, as in old Perl. I have now made octal escapes with
1140     values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1141     translate to the appropriate multibyte character.
1142    
1143     29. Applied some refactoring to reduce the number of warnings from Microsoft
1144     and Borland compilers. This has included removing the fudge introduced
1145     seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1146     a warning about an unused variable.
1147    
1148     21. PCRE has not included VT (character 0x0b) in the set of whitespace
1149     characters since release 4.0, because Perl (from release 5.004) does not.
1150     [Or at least, is documented not to: some releases seem to be in conflict
1151     with the documentation.] However, when a pattern was studied with
1152     pcre_study() and all its branches started with \s, PCRE still included VT
1153     as a possible starting character. Of course, this did no harm; it just
1154     caused an unnecessary match attempt.
1155    
1156     22. Removed a now-redundant internal flag bit that recorded the fact that case
1157     dependency changed within the pattern. This was once needed for "required
1158     byte" processing, but is no longer used. This recovers a now-scarce options
1159     bit. Also moved the least significant internal flag bit to the most-
1160     significant bit of the word, which was not previously used (hangover from
1161     the days when it was an int rather than a uint) to free up another bit for
1162     the future.
1163    
1164     23. Added support for CRLF line endings as well as CR and LF. As well as the
1165     default being selectable at build time, it can now be changed at runtime
1166     via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1167     specify that it is scanning data with non-default line endings.
1168    
1169     24. Changed the definition of CXXLINK to make it agree with the definition of
1170     LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1171    
1172     25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1173     recursions. This makes a big different to stack usage for some patterns.
1174    
1175     26. If a subpattern containing a named recursion or subroutine reference such
1176     as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1177     the space required for the compiled pattern went wrong and gave too small a
1178     value. Depending on the environment, this could lead to "Failed: internal
1179     error: code overflow at offset 49" or "glibc detected double free or
1180     corruption" errors.
1181    
1182     27. Applied patches from Google (a) to support the new newline modes and (b) to
1183     advance over multibyte UTF-8 characters in GlobalReplace.
1184    
1185     28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1186     difference for some implementation of PCRE in some Windows version.
1187    
1188     29. Added some extra testing facilities to pcretest:
1189    
1190     \q<number> in a data line sets the "match limit" value
1191     \Q<number> in a data line sets the "match recursion limt" value
1192     -S <number> sets the stack size, where <number> is in megabytes
1193    
1194     The -S option isn't available for Windows.
1195    
1196    
1197 nigel 89 Version 6.6 06-Feb-06
1198     ---------------------
1199    
1200     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1201     in pcreposix.h. I have copied the definition from pcre.h.
1202    
1203     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1204     because pcre.h is no longer a built file.
1205    
1206     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1207     not normally included in the compiled code.
1208    
1209    
1210 nigel 87 Version 6.5 01-Feb-06
1211     ---------------------
1212    
1213     1. When using the partial match feature with pcre_dfa_exec(), it was not
1214     anchoring the second and subsequent partial matches at the new starting
1215     point. This could lead to incorrect results. For example, with the pattern
1216     /1234/, partially matching against "123" and then "a4" gave a match.
1217    
1218     2. Changes to pcregrep:
1219    
1220     (a) All non-match returns from pcre_exec() were being treated as failures
1221     to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
1222     error message is output. Some extra information is given for the
1223     PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
1224     probably the only errors that are likely to be caused by users (by
1225     specifying a regex that has nested indefinite repeats, for instance).
1226     If there are more than 20 of these errors, pcregrep is abandoned.
1227    
1228     (b) A binary zero was treated as data while matching, but terminated the
1229     output line if it was written out. This has been fixed: binary zeroes
1230     are now no different to any other data bytes.
1231    
1232     (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
1233     used to set a locale for matching. The --locale=xxxx long option has
1234     been added (no short equivalent) to specify a locale explicitly on the
1235     pcregrep command, overriding the environment variables.
1236    
1237     (d) When -B was used with -n, some line numbers in the output were one less
1238     than they should have been.
1239    
1240     (e) Added the -o (--only-matching) option.
1241    
1242     (f) If -A or -C was used with -c (count only), some lines of context were
1243     accidentally printed for the final match.
1244    
1245     (g) Added the -H (--with-filename) option.
1246    
1247     (h) The combination of options -rh failed to suppress file names for files
1248     that were found from directory arguments.
1249    
1250     (i) Added the -D (--devices) and -d (--directories) options.
1251    
1252     (j) Added the -F (--fixed-strings) option.
1253    
1254     (k) Allow "-" to be used as a file name for -f as well as for a data file.
1255    
1256     (l) Added the --colo(u)r option.
1257    
1258     (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
1259     is not present by default.
1260    
1261     3. A nasty bug was discovered in the handling of recursive patterns, that is,
1262     items such as (?R) or (?1), when the recursion could match a number of
1263     alternatives. If it matched one of the alternatives, but subsequently,
1264     outside the recursion, there was a failure, the code tried to back up into
1265     the recursion. However, because of the way PCRE is implemented, this is not
1266     possible, and the result was an incorrect result from the match.
1267    
1268     In order to prevent this happening, the specification of recursion has
1269     been changed so that all such subpatterns are automatically treated as
1270     atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
1271    
1272     4. I had overlooked the fact that, in some locales, there are characters for
1273     which isalpha() is true but neither isupper() nor islower() are true. In
1274     the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
1275     and ordfeminine) are like this. This affected the treatment of \w and \W
1276     when they appeared in character classes, but not when they appeared outside
1277     a character class. The bit map for "word" characters is now created
1278     separately from the results of isalnum() instead of just taking it from the
1279     upper, lower, and digit maps. (Plus the underscore character, of course.)
1280    
1281     5. The above bug also affected the handling of POSIX character classes such as
1282     [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
1283     permanent tables. Instead, the bit maps for such a class were previously
1284     created as the appropriate unions of the upper, lower, and digit bitmaps.
1285     Now they are created by subtraction from the [[:word:]] class, which has
1286     its own bitmap.
1287    
1288     6. The [[:blank:]] character class matches horizontal, but not vertical space.
1289     It is created by subtracting the vertical space characters (\x09, \x0a,
1290     \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
1291     subtraction was done in the overall bitmap for a character class, meaning
1292     that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
1293     be recognized. This bug has been fixed.
1294    
1295     7. Patches from the folks at Google:
1296    
1297     (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
1298     real life, but is still worth protecting against".
1299    
1300     (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
1301     regular expressions".
1302    
1303     (c) pcre_scanner.cc: avoid use of std::count() because not all systems
1304     have it.
1305    
1306     (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
1307     "configure" and the latter not, in order to fix a problem somebody had
1308     with compiling the Arg class on HP-UX.
1309    
1310     (e) Improve the error-handling of the C++ wrapper a little bit.
1311    
1312     (f) New tests for checking recursion limiting.
1313    
1314     8. The pcre_memmove() function, which is used only if the environment does not
1315     have a standard memmove() function (and is therefore rarely compiled),
1316     contained two bugs: (a) use of int instead of size_t, and (b) it was not
1317     returning a result (though PCRE never actually uses the result).
1318    
1319     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
1320     large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
1321     returned instead of calling malloc() with an overflowing number that would
1322     most likely cause subsequent chaos.
1323    
1324     10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
1325    
1326     11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
1327     with this option is matched, the nmatch and pmatch options of regexec() are
1328     ignored.
1329    
1330     12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
1331     provided in case anyone wants to the the POSIX interface with UTF-8
1332     strings.
1333    
1334     13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
1335     C++ linking (needed for some HP-UX environments).
1336    
1337     14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
1338     (unused parameter) and in the pcre_printint() function (omitted "default"
1339     switch label when the default is to do nothing).
1340    
1341     15. Added some code to make it possible, when PCRE is compiled as a C++
1342     library, to replace subject pointers for pcre_exec() with a smart pointer
1343     class, thus making it possible to process discontinuous strings.
1344    
1345     16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
1346     much the same function. They were added by different people who were trying
1347     to make PCRE easy to compile on non-Unix systems. It has been suggested
1348     that PCRE_EXPORT be abolished now that there is more automatic apparatus
1349     for compiling on Windows systems. I have therefore replaced it with
1350     PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
1351     defaults to "extern" for C or "extern C" for C++, which works fine on
1352     Unix-like systems. It is now possible to override the value of PCRE_DATA_
1353     SCOPE with something explicit in config.h. In addition:
1354    
1355     (a) pcreposix.h still had just "extern" instead of either of these macros;
1356     I have replaced it with PCRE_DATA_SCOPE.
1357    
1358     (b) Functions such as _pcre_xclass(), which are internal to the library,
1359     but external in the C sense, all had PCRE_EXPORT in their definitions.
1360     This is apparently wrong for the Windows case, so I have removed it.
1361     (It makes no difference on Unix-like systems.)
1362    
1363     17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
1364     of recursive calls to match(). This is different to MATCH_LIMIT because
1365     that limits the total number of calls to match(), not all of which increase
1366     the depth of recursion. Limiting the recursion depth limits the amount of
1367     stack (or heap if NO_RECURSE is set) that is used. The default can be set
1368     when PCRE is compiled, and changed at run time. A patch from Google adds
1369     this functionality to the C++ interface.
1370    
1371     18. Changes to the handling of Unicode character properties:
1372    
1373     (a) Updated the table to Unicode 4.1.0.
1374    
1375     (b) Recognize characters that are not in the table as "Cn" (undefined).
1376    
1377     (c) I revised the way the table is implemented to a much improved format
1378     which includes recognition of ranges. It now supports the ranges that
1379     are defined in UnicodeData.txt, and it also amalgamates other
1380     characters into ranges. This has reduced the number of entries in the
1381     table from around 16,000 to around 3,000, thus reducing its size
1382     considerably. I realized I did not need to use a tree structure after
1383     all - a binary chop search is just as efficient. Having reduced the
1384     number of entries, I extended their size from 6 bytes to 8 bytes to
1385     allow for more data.
1386    
1387     (d) Added support for Unicode script names via properties such as \p{Han}.
1388    
1389     19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
1390     matching that character.
1391    
1392     20. When matching a repeated Unicode property with a minimum greater than zero,
1393     (for example \pL{2,}), PCRE could look past the end of the subject if it
1394     reached it while seeking the minimum number of characters. This could
1395     happen only if some of the characters were more than one byte long, because
1396     there is a check for at least the minimum number of bytes.
1397    
1398     21. Refactored the implementation of \p and \P so as to be more general, to
1399     allow for more different types of property in future. This has changed the
1400     compiled form incompatibly. Anybody with saved compiled patterns that use
1401     \p or \P will have to recompile them.
1402    
1403     22. Added "Any" and "L&" to the supported property types.
1404    
1405     23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
1406     but give a compile time error if the value is greater than 0xff.
1407    
1408     24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
1409     accidentally not being installed or uninstalled.
1410    
1411     25. The pcre.h file was built from pcre.h.in, but the only changes that were
1412     made were to insert the current release number. This seemed silly, because
1413     it made things harder for people building PCRE on systems that don't run
1414     "configure". I have turned pcre.h into a distributed file, no longer built
1415     by "configure", with the version identification directly included. There is
1416     no longer a pcre.h.in file.
1417    
1418     However, this change necessitated a change to the pcre-config script as
1419     well. It is built from pcre-config.in, and one of the substitutions was the
1420     release number. I have updated configure.ac so that ./configure now finds
1421     the release number by grepping pcre.h.
1422    
1423     26. Added the ability to run the tests under valgrind.
1424    
1425    
1426 nigel 85 Version 6.4 05-Sep-05
1427     ---------------------
1428    
1429     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
1430     "--" to be printed when multiple files were scanned, even when none of the
1431     -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
1432     consider it to be a bug, and have restored the previous behaviour.
1433    
1434     2. A couple of code tidies to get rid of compiler warnings.
1435    
1436     3. The pcretest program used to cheat by referring to symbols in the library
1437     whose names begin with _pcre_. These are internal symbols that are not
1438     really supposed to be visible externally, and in some environments it is
1439     possible to suppress them. The cheating is now confined to including
1440     certain files from the library's source, which is a bit cleaner.
1441    
1442     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
1443     file's purpose clearer.
1444    
1445     5. Reorganized pcre_ucp_findchar().
1446    
1447    
1448 nigel 83 Version 6.3 15-Aug-05
1449     ---------------------
1450    
1451     1. The file libpcre.pc.in did not have general read permission in the tarball.
1452    
1453     2. There were some problems when building without C++ support:
1454    
1455     (a) If C++ support was not built, "make install" and "make test" still
1456     tried to test it.
1457    
1458     (b) There were problems when the value of CXX was explicitly set. Some
1459     changes have been made to try to fix these, and ...
1460    
1461     (c) --disable-cpp can now be used to explicitly disable C++ support.
1462    
1463     (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
1464     backslash in a target when C++ was disabled. This confuses some
1465     versions of "make", apparently. Using an intermediate variable solves
1466     this. (Same for CPP_LOBJ.)
1467    
1468     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
1469     (non-Windows) now includes $(CFLAGS) because these flags are sometimes
1470     necessary on certain architectures.
1471    
1472     4. Added a setting of -export-symbols-regex to the link command to remove
1473     those symbols that are exported in the C sense, but actually are local
1474     within the library, and not documented. Their names all begin with
1475     "_pcre_". This is not a perfect job, because (a) we have to except some
1476     symbols that pcretest ("illegally") uses, and (b) the facility isn't always
1477     available (and never for static libraries). I have made a note to try to
1478     find a way round (a) in the future.
1479    
1480    
1481 nigel 81 Version 6.2 01-Aug-05
1482     ---------------------
1483    
1484     1. There was no test for integer overflow of quantifier values. A construction
1485     such as {1111111111111111} would give undefined results. What is worse, if
1486     a minimum quantifier for a parenthesized subpattern overflowed and became
1487     negative, the calculation of the memory size went wrong. This could have
1488     led to memory overwriting.
1489    
1490     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
1491    
1492     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
1493     operating environments where this matters.
1494    
1495     4. Applied Giuseppe Maxia's patch to add additional features for controlling
1496     PCRE options from within the C++ wrapper.
1497    
1498     5. Named capturing subpatterns were not being correctly counted when a pattern
1499     was compiled. This caused two problems: (a) If there were more than 100
1500     such subpatterns, the calculation of the memory needed for the whole
1501     compiled pattern went wrong, leading to an overflow error. (b) Numerical
1502     back references of the form \12, where the number was greater than 9, were
1503     not recognized as back references, even though there were sufficient
1504     previous subpatterns.
1505    
1506     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
1507     versions of gcc, e.g. 2.95.4.
1508    
1509    
1510 nigel 79 Version 6.1 21-Jun-05
1511     ---------------------
1512    
1513     1. There was one reference to the variable "posix" in pcretest.c that was not
1514     surrounded by "#if !defined NOPOSIX".
1515    
1516     2. Make it possible to compile pcretest without DFA support, UTF8 support, or
1517     the cross-check on the old pcre_info() function, for the benefit of the
1518     cut-down version of PCRE that is currently imported into Exim.
1519    
1520     3. A (silly) pattern starting with (?i)(?-i) caused an internal space
1521     allocation error. I've done the easy fix, which wastes 2 bytes for sensible
1522     patterns that start (?i) but I don't think that matters. The use of (?i) is
1523     just an example; this all applies to the other options as well.
1524    
1525     4. Since libtool seems to echo the compile commands it is issuing, the output
1526     from "make" can be reduced a bit by putting "@" in front of each libtool
1527     compile command.
1528    
1529     5. Patch from the folks at Google for configure.in to be a bit more thorough
1530     in checking for a suitable C++ installation before trying to compile the
1531     C++ stuff. This should fix a reported problem when a compiler was present,
1532     but no suitable headers.
1533    
1534     6. The man pages all had just "PCRE" as their title. I have changed them to
1535     be the relevant file name. I have also arranged that these names are
1536     retained in the file doc/pcre.txt, which is a concatenation in text format
1537     of all the man pages except the little individual ones for each function.
1538    
1539     7. The NON-UNIX-USE file had not been updated for the different set of source
1540     files that come with release 6. I also added a few comments about the C++
1541     wrapper.
1542    
1543    
1544 nigel 77 Version 6.0 07-Jun-05
1545     ---------------------
1546    
1547     1. Some minor internal re-organization to help with my DFA experiments.
1548    
1549     2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
1550     didn't matter for the library itself when fully configured, but did matter
1551     when compiling without UCP support, or within Exim, where the ucp files are
1552     not imported.
1553    
1554     3. Refactoring of the library code to split up the various functions into
1555     different source modules. The addition of the new DFA matching code (see
1556     below) to a single monolithic source would have made it really too
1557     unwieldy, quite apart from causing all the code to be include in a
1558     statically linked application, when only some functions are used. This is
1559     relevant even without the DFA addition now that patterns can be compiled in
1560     one application and matched in another.
1561    
1562     The downside of splitting up is that there have to be some external
1563     functions and data tables that are used internally in different modules of
1564     the library but which are not part of the API. These have all had their
1565     names changed to start with "_pcre_" so that they are unlikely to clash
1566     with other external names.
1567    
1568     4. Added an alternate matching function, pcre_dfa_exec(), which matches using
1569     a different (DFA) algorithm. Although it is slower than the original
1570     function, it does have some advantages for certain types of matching
1571     problem.
1572    
1573     5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
1574     including restarting after a partial match.
1575    
1576     6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
1577     defined when compiling for Windows was sent to me. I have put it into the
1578     code, though I have no means of testing or verifying it.
1579    
1580     7. Added the pcre_refcount() auxiliary function.
1581    
1582     8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
1583     match before or at the first newline in the subject string. In pcretest,
1584     the /f option on a pattern can be used to set this.
1585    
1586     9. A repeated \w when used in UTF-8 mode with characters greater than 256
1587     would behave wrongly. This has been present in PCRE since release 4.0.
1588    
1589     10. A number of changes to the pcregrep command:
1590    
1591     (a) Refactored how -x works; insert ^(...)$ instead of setting
1592     PCRE_ANCHORED and checking the length, in preparation for adding
1593     something similar for -w.
1594    
1595     (b) Added the -w (match as a word) option.
1596    
1597     (c) Refactored the way lines are read and buffered so as to have more
1598     than one at a time available.
1599    
1600     (d) Implemented a pcregrep test script.
1601    
1602     (e) Added the -M (multiline match) option. This allows patterns to match
1603     over several lines of the subject. The buffering ensures that at least
1604     8K, or the rest of the document (whichever is the shorter) is available
1605     for matching (and similarly the previous 8K for lookbehind assertions).
1606    
1607     (f) Changed the --help output so that it now says
1608    
1609     -w, --word-regex(p)
1610    
1611     instead of two lines, one with "regex" and the other with "regexp"
1612     because that confused at least one person since the short forms are the
1613     same. (This required a bit of code, as the output is generated
1614     automatically from a table. It wasn't just a text change.)
1615    
1616     (g) -- can be used to terminate pcregrep options if the next thing isn't an
1617     option but starts with a hyphen. Could be a pattern or a path name
1618     starting with a hyphen, for instance.
1619    
1620     (h) "-" can be given as a file name to represent stdin.
1621    
1622     (i) When file names are being printed, "(standard input)" is used for
1623     the standard input, for compatibility with GNU grep. Previously
1624     "<stdin>" was used.
1625    
1626     (j) The option --label=xxx can be used to supply a name to be used for
1627     stdin when file names are being printed. There is no short form.
1628    
1629     (k) Re-factored the options decoding logic because we are going to add
1630     two more options that take data. Such options can now be given in four
1631     different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
1632    
1633     (l) Added the -A, -B, and -C options for requesting that lines of context
1634     around matches be printed.
1635    
1636     (m) Added the -L option to print the names of files that do not contain
1637     any matching lines, that is, the complement of -l.
1638    
1639     (n) The return code is 2 if any file cannot be opened, but pcregrep does
1640     continue to scan other files.
1641    
1642     (o) The -s option was incorrectly implemented. For compatibility with other
1643     greps, it now suppresses the error message for a non-existent or non-
1644     accessible file (but not the return code). There is a new option called
1645     -q that suppresses the output of matching lines, which was what -s was
1646     previously doing.
1647    
1648     (p) Added --include and --exclude options to specify files for inclusion
1649     and exclusion when recursing.
1650    
1651     11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
1652     Hopefully, it now does.
1653    
1654     12. Missing cast in pcre_study().
1655    
1656     13. Added an "uninstall" target to the makefile.
1657    
1658     14. Replaced "extern" in the function prototypes in Makefile.in with
1659     "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
1660     world, but is set differently for Windows.
1661    
1662     15. Added a second compiling function called pcre_compile2(). The only
1663     difference is that it has an extra argument, which is a pointer to an
1664     integer error code. When there is a compile-time failure, this is set
1665     non-zero, in addition to the error test pointer being set to point to an
1666     error message. The new argument may be NULL if no error number is required
1667     (but then you may as well call pcre_compile(), which is now just a
1668     wrapper). This facility is provided because some applications need a
1669     numeric error indication, but it has also enabled me to tidy up the way
1670     compile-time errors are handled in the POSIX wrapper.
1671    
1672     16. Added VPATH=.libs to the makefile; this should help when building with one
1673     prefix path and installing with another. (Or so I'm told by someone who
1674     knows more about this stuff than I do.)
1675    
1676     17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
1677     passes PCRE_DOTALL to the pcre_compile() function, making the "." character
1678     match everything, including newlines. This is not POSIX-compatible, but
1679     somebody wanted the feature. From pcretest it can be activated by using
1680     both the P and the s flags.
1681    
1682     18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
1683    
1684     19. libpcre.pc was being incorrectly installed as executable.
1685    
1686     20. A couple of places in pcretest check for end-of-line by looking for '\n';
1687     it now also looks for '\r' so that it will work unmodified on Windows.
1688    
1689     21. Added Google's contributed C++ wrapper to the distribution.
1690    
1691     22. Added some untidy missing memory free() calls in pcretest, to keep
1692     Electric Fence happy when testing.
1693    
1694    
1695    
1696 nigel 75 Version 5.0 13-Sep-04
1697     ---------------------
1698    
1699     1. Internal change: literal characters are no longer packed up into items
1700     containing multiple characters in a single byte-string. Each character
1701     is now matched using a separate opcode. However, there may be more than one
1702     byte in the character in UTF-8 mode.
1703    
1704     2. The pcre_callout_block structure has two new fields: pattern_position and
1705     next_item_length. These contain the offset in the pattern to the next match
1706     item, and its length, respectively.
1707    
1708     3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
1709     insertion of callouts before each pattern item. Added the /C option to
1710     pcretest to make use of this.
1711    
1712     4. On the advice of a Windows user, the lines
1713    
1714     #if defined(_WIN32) || defined(WIN32)
1715     _setmode( _fileno( stdout ), 0x8000 );
1716     #endif /* defined(_WIN32) || defined(WIN32) */
1717    
1718     have been added to the source of pcretest. This apparently does useful
1719     magic in relation to line terminators.
1720    
1721     5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
1722     for the benefit of those environments where the "b" makes a difference.
1723    
1724     6. The icc compiler has the same options as gcc, but "configure" doesn't seem
1725     to know about it. I have put a hack into configure.in that adds in code
1726     to set GCC=yes if CC=icc. This seems to end up at a point in the
1727     generated configure script that is early enough to affect the setting of
1728     compiler options, which is what is needed, but I have no means of testing
1729     whether it really works. (The user who reported this had patched the
1730     generated configure script, which of course I cannot do.)
1731    
1732     LATER: After change 22 below (new libtool files), the configure script
1733     seems to know about icc (and also ecc). Therefore, I have commented out
1734     this hack in configure.in.
1735    
1736     7. Added support for pkg-config (2 patches were sent in).
1737    
1738     8. Negated POSIX character classes that used a combination of internal tables
1739     were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
1740     [[:^ascii]]. Typically, they would match almost any characters. The other
1741     POSIX classes were not broken in this way.
1742    
1743     9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
1744     to find the match, as PCRE was deluded into thinking that the match had to
1745     start at the start point or following a newline. The same bug applied to
1746     patterns with negative forward assertions or any backward assertions
1747     preceding ".*" at the start, unless the pattern required a fixed first
1748     character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
1749    
1750     10. In UTF-8 mode, when moving forwards in the subject after a failed match
1751     starting at the last subject character, bytes beyond the end of the subject
1752     string were read.
1753    
1754     11. Renamed the variable "class" as "classbits" to make life easier for C++
1755     users. (Previously there was a macro definition, but it apparently wasn't
1756     enough.)
1757    
1758     12. Added the new field "tables" to the extra data so that tables can be passed
1759     in at exec time, or the internal tables can be re-selected. This allows
1760     a compiled regex to be saved and re-used at a later time by a different
1761     program that might have everything at different addresses.
1762    
1763     13. Modified the pcre-config script so that, when run on Solaris, it shows a
1764     -R library as well as a -L library.
1765    
1766     14. The debugging options of pcretest (-d on the command line or D on a
1767     pattern) showed incorrect output for anything following an extended class
1768     that contained multibyte characters and which was followed by a quantifier.
1769    
1770     15. Added optional support for general category Unicode character properties
1771     via the \p, \P, and \X escapes. Unicode property support implies UTF-8
1772     support. It adds about 90K to the size of the library. The meanings of the
1773     inbuilt class escapes such as \d and \s have NOT been changed.
1774    
1775     16. Updated pcredemo.c to include calls to free() to release the memory for the
1776     compiled pattern.
1777    
1778     17. The generated file chartables.c was being created in the source directory
1779     instead of in the building directory. This caused the build to fail if the
1780     source directory was different from the building directory, and was
1781     read-only.
1782    
1783     18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
1784     file. No doubt somebody will tell me if they don't make sense... Also added
1785     Dan Mooney's comments about building on OpenVMS.
1786    
1787     19. Added support for partial matching via the PCRE_PARTIAL option for
1788     pcre_exec() and the \P data escape in pcretest.
1789    
1790     20. Extended pcretest with 3 new pattern features:
1791    
1792     (i) A pattern option of the form ">rest-of-line" causes pcretest to
1793     write the compiled pattern to the file whose name is "rest-of-line".
1794     This is a straight binary dump of the data, with the saved pointer to
1795     the character tables forced to be NULL. The study data, if any, is
1796     written too. After writing, pcretest reads a new pattern.
1797    
1798     (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
1799     compiled pattern from the given file. There must not be any
1800     occurrences of "<" in the file name (pretty unlikely); if there are,
1801     pcretest will instead treat the initial "<" as a pattern delimiter.
1802     After reading in the pattern, pcretest goes on to read data lines as
1803     usual.
1804    
1805     (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
1806     and 16-bit fields in a compiled pattern, to simulate a pattern that
1807     was compiled on a host of opposite endianness.
1808    
1809     21. The pcre-exec() function can now cope with patterns that were compiled on
1810     hosts of opposite endianness, with this restriction:
1811    
1812     As for any compiled expression that is saved and used later, the tables
1813     pointer field cannot be preserved; the extra_data field in the arguments
1814     to pcre_exec() should be used to pass in a tables address if a value
1815     other than the default internal tables were used at compile time.
1816    
1817     22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
1818     now diagnosed as an error. Previously, most of the time, a negative number
1819     would have been treated as zero, but if in addition "ovector" was passed as
1820     NULL, a crash could occur.
1821    
1822     23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
1823     new versions from the libtool 1.5 distribution (the last one is a copy of
1824     a file called libtool.m4). This seems to have fixed the need to patch
1825     "configure" to support Darwin 1.3 (which I used to do). However, I still
1826     had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
1827     workstation).
1828    
1829     24. Changed the PCRE licence to be the more standard "BSD" licence.
1830    
1831    
1832 nigel 73 Version 4.5 01-Dec-03
1833     ---------------------
1834    
1835     1. There has been some re-arrangement of the code for the match() function so
1836     that it can be compiled in a version that does not call itself recursively.
1837     Instead, it keeps those local variables that need separate instances for
1838     each "recursion" in a frame on the heap, and gets/frees frames whenever it
1839     needs to "recurse". Keeping track of where control must go is done by means
1840     of setjmp/longjmp. The whole thing is implemented by a set of macros that
1841     hide most of the details from the main code, and operates only if
1842     NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
1843     "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
1844     operating.
1845    
1846     To make it easier for callers to provide specially tailored get/free
1847     functions for this usage, two new functions, pcre_stack_malloc, and
1848     pcre_stack_free, are used. They are always called in strict stacking order,
1849     and the size of block requested is always the same.
1850    
1851     The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
1852     PCRE has been compiled to use the stack or the heap for recursion. The
1853     -C option of pcretest uses this to show which version is compiled.
1854    
1855     A new data escape \S, is added to pcretest; it causes the amounts of store
1856     obtained and freed by both kinds of malloc/free at match time to be added
1857     to the output.
1858    
1859     2. Changed the locale test to use "fr_FR" instead of "fr" because that's
1860     what's available on my current Linux desktop machine.
1861    
1862     3. When matching a UTF-8 string, the test for a valid string at the start has
1863     been extended. If start_offset is not zero, PCRE now checks that it points
1864     to a byte that is the start of a UTF-8 character. If not, it returns
1865     PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
1866     this is necessary because there may be backward assertions in the pattern.
1867     When matching the same subject several times, it may save resources to use
1868     PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
1869    
1870     4. The code for checking the validity of UTF-8 strings has been tightened so
1871     that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
1872     containing "overlong sequences".
1873    
1874     5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
1875     I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
1876     should have been "&", but it just so happened that all the cases this let
1877     through by mistake were picked up later in the function.
1878    
1879     6. I had used a variable called "isblank" - this is a C99 function, causing
1880     some compilers to warn. To avoid this, I renamed it (as "blankclass").
1881    
1882     7. Cosmetic: (a) only output another newline at the end of pcretest if it is
1883     prompting; (b) run "./pcretest /dev/null" at the start of the test script
1884     so the version is shown; (c) stop "make test" echoing "./RunTest".
1885    
1886     8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
1887    
1888     9. The prototype for memmove() for systems that don't have it was using
1889     size_t, but the inclusion of the header that defines size_t was later. I've
1890     moved the #includes for the C headers earlier to avoid this.
1891    
1892     10. Added some adjustments to the code to make it easier to compiler on certain
1893     special systems:
1894    
1895     (a) Some "const" qualifiers were missing.
1896     (b) Added the macro EXPORT before all exported functions; by default this
1897     is defined to be empty.
1898     (c) Changed the dftables auxiliary program (that builds chartables.c) so
1899     that it reads its output file name as an argument instead of writing
1900     to the standard output and assuming this can be redirected.
1901    
1902     11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
1903     class containing characters with values greater than 255, PCRE compilation
1904     went into a loop.
1905    
1906     12. A recursive reference to a subpattern that was within another subpattern
1907     that had a minimum quantifier of zero caused PCRE to crash. For example,
1908     (x(y(?2))z)? provoked this bug with a subject that got as far as the
1909     recursion. If the recursively-called subpattern itself had a zero repeat,
1910     that was OK.
1911    
1912     13. In pcretest, the buffer for reading a data line was set at 30K, but the
1913     buffer into which it was copied (for escape processing) was still set at
1914     1024, so long lines caused crashes.
1915    
1916     14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
1917     "internal error: code overflow...". This applied to any character class
1918     that was followed by a possessive quantifier.
1919    
1920     15. Modified the Makefile to add libpcre.la as a prerequisite for
1921     libpcreposix.la because I was told this is needed for a parallel build to
1922     work.
1923    
1924     16. If a pattern that contained .* following optional items at the start was
1925     studied, the wrong optimizing data was generated, leading to matching
1926     errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
1927     matching string must start with a or b or c. The correct conclusion for
1928     this pattern is that a match can start with any character.
1929    
1930    
1931 nigel 71 Version 4.4 13-Aug-03
1932     ---------------------
1933    
1934     1. In UTF-8 mode, a character class containing characters with values between
1935     127 and 255 was not handled correctly if the compiled pattern was studied.
1936     In fixing this, I have also improved the studying algorithm for such
1937     classes (slightly).
1938    
1939     2. Three internal functions had redundant arguments passed to them. Removal
1940     might give a very teeny performance improvement.
1941    
1942     3. Documentation bug: the value of the capture_top field in a callout is *one
1943     more than* the number of the hightest numbered captured substring.
1944    
1945     4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
1946     in incorrectly linking with a previously installed version. They now link
1947     explicitly with libpcre.la.
1948    
1949     5. configure.in no longer needs to recognize Cygwin specially.
1950    
1951     6. A problem in pcre.in for Windows platforms is fixed.
1952    
1953     7. If a pattern was successfully studied, and the -d (or /D) flag was given to
1954     pcretest, it used to include the size of the study block as part of its
1955     output. Unfortunately, the structure contains a field that has a different
1956     size on different hardware architectures. This meant that the tests that
1957     showed this size failed. As the block is currently always of a fixed size,
1958     this information isn't actually particularly useful in pcretest output, so
1959     I have just removed it.
1960    
1961     8. Three pre-processor statements accidentally did not start in column 1.
1962     Sadly, there are *still* compilers around that complain, even though
1963     standard C has not required this for well over a decade. Sigh.
1964    
1965     9. In pcretest, the code for checking callouts passed small integers in the
1966     callout_data field, which is a void * field. However, some picky compilers
1967     complained about the casts involved for this on 64-bit systems. Now
1968     pcretest passes the address of the small integer instead, which should get
1969     rid of the warnings.
1970    
1971     10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
1972     both compile and run time, and gives an error if an invalid UTF-8 sequence
1973     is found. There is a option for disabling this check in cases where the
1974     string is known to be correct and/or the maximum performance is wanted.
1975    
1976     11. In response to a bug report, I changed one line in Makefile.in from
1977    
1978     -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
1979     to
1980     -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
1981    
1982     to look similar to other lines, but I have no way of telling whether this
1983     is the right thing to do, as I do not use Windows. No doubt I'll get told
1984     if it's wrong...
1985    
1986    
1987 nigel 69 Version 4.3 21-May-03
1988     ---------------------
1989    
1990     1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
1991     Makefile.
1992    
1993     2. Some refactoring to improve the quality of the code:
1994    
1995     (i) The utf8_table... variables are now declared "const".
1996    
1997     (ii) The code for \cx, which used the "case flipping" table to upper case
1998     lower case letters, now just substracts 32. This is ASCII-specific,
1999     but the whole concept of \cx is ASCII-specific, so it seems
2000     reasonable.
2001    
2002     (iii) PCRE was using its character types table to recognize decimal and
2003     hexadecimal digits in the pattern. This is silly, because it handles
2004     only 0-9, a-f, and A-F, but the character types table is locale-
2005     specific, which means strange things might happen. A private
2006     table is now used for this - though it costs 256 bytes, a table is
2007     much faster than multiple explicit tests. Of course, the standard
2008     character types table is still used for matching digits in subject
2009     strings against \d.
2010    
2011     (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
2012     ending in _t are). So I've renamed it as ESC_tee.
2013    
2014     3. The first argument for regexec() in the POSIX wrapper should have been
2015     defined as "const".
2016    
2017     4. Changed pcretest to use malloc() for its buffers so that they can be
2018     Electric Fenced for debugging.
2019    
2020     5. There were several places in the code where, in UTF-8 mode, PCRE would try
2021     to read one or more bytes before the start of the subject string. Often this
2022     had no effect on PCRE's behaviour, but in some circumstances it could
2023     provoke a segmentation fault.
2024    
2025     6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
2026     to try to read one or more bytes before the start of the subject string.
2027    
2028     7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
2029     UTF-8 support could misbehave in various ways if the subject string
2030     contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
2031     area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
2032     back over UTF-8 characters.)
2033    
2034    
2035 nigel 67 Version 4.2 14-Apr-03
2036     ---------------------
2037    
2038     1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
2039    
2040     2. Changes to the building process, supplied by Ronald Landheer-Cieslak
2041     [ON_WINDOWS]: new variable, "#" on non-Windows platforms
2042     [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
2043     [WIN_PREFIX]: new variable, "cyg" for Cygwin
2044     * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
2045     and BUILD_EXEEXT
2046     Note: automatic setting of the BUILD variables is not yet working
2047     set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
2048     compile-time but not at link-time
2049     [LINK]: use for linking executables only
2050     make different versions for Windows and non-Windows
2051     [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
2052     libraries
2053     [LINK_FOR_BUILD]: new variable
2054     [OBJEXT]: use throughout
2055     [EXEEXT]: use throughout
2056     <winshared>: new target
2057     <wininstall>: new target
2058     <dftables.o>: use native compiler
2059     <dftables>: use native linker
2060     <install>: handle Windows platform correctly
2061     <clean>: ditto
2062     <check>: ditto
2063     copy DLL to top builddir before testing
2064    
2065     As part of these changes, -no-undefined was removed again. This was reported
2066     to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
2067     in any case.
2068    
2069     3. Some tidies to get rid of compiler warnings:
2070    
2071     . In the match_data structure, match_limit was an unsigned long int, whereas
2072     match_call_count was an int. I've made them both unsigned long ints.
2073    
2074     . In pcretest the fact that a const uschar * doesn't automatically cast to
2075     a void * provoked a warning.
2076    
2077     . Turning on some more compiler warnings threw up some "shadow" variables
2078     and a few more missing casts.
2079    
2080     4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
2081     option, a class that contained a single character with a value between 128
2082     and 255 (e.g. /[\xFF]/) caused PCRE to crash.
2083    
2084     5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
2085     option, a class that contained several characters, but with at least one
2086     whose value was between 128 and 255 caused PCRE to crash.
2087    
2088    
2089 nigel 65 Version 4.1 12-Mar-03
2090     ---------------------
2091 nigel 63
2092 nigel 65 1. Compiling with gcc -pedantic found a couple of places where casts were
2093     needed, and a string in dftables.c that was longer than standard compilers are
2094     required to support.
2095    
2096     2. Compiling with Sun's compiler found a few more places where the code could
2097     be tidied up in order to avoid warnings.
2098    
2099     3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
2100     first of these names is deprecated in the latest Autoconf in favour of the name
2101     CC_FOR_BUILD, because "host" is typically used to mean the system on which the
2102     compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
2103     analogy I have changed it to CFLAGS_FOR_BUILD.
2104    
2105     4. Added -no-undefined to the linking command in the Makefile, because this is
2106     apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
2107     linking step for the pcreposix library.
2108    
2109     5. PCRE was failing to diagnose the case of two named groups with the same
2110     name.
2111    
2112     6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
2113     literal character that is needed in the subject for a match, and scans along to
2114     ensure that it is present before embarking on the full matching process. This
2115     saves time in cases of nested unlimited repeats that are never going to match.
2116     Problem: the scan can take a lot of time if the subject is very long (e.g.
2117     megabytes), thus penalizing straightforward matches. It is now done only if the
2118     amount of subject to be scanned is less than 1000 bytes.
2119    
2120     7. A lesser problem with the same optimization is that it was recording the
2121     first character of an anchored pattern as "needed", thus provoking a search
2122     right along the subject, even when the first match of the pattern was going to
2123     fail. The "needed" character is now not set for anchored patterns, unless it
2124     follows something in the pattern that is of non-fixed length. Thus, it still
2125     fulfils its original purpose of finding quick non-matches in cases of nested
2126     unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
2127    
2128    
2129     Version 4.0 17-Feb-03
2130     ---------------------
2131    
2132 nigel 63 1. If a comment in an extended regex that started immediately after a meta-item
2133     extended to the end of string, PCRE compiled incorrect data. This could lead to
2134     all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
2135    
2136     2. Moved to autoconf 2.53 and libtool 1.4.2.
2137    
2138     3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
2139     the special perltest8 script is no longer needed - all the tests can be run
2140     from a single perltest script.
2141    
2142     4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
2143     by \s. It has now been removed in PCRE. This means it isn't recognized as
2144     whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
2145     class [:space:] *does* include VT, thereby creating a mess.
2146    
2147     5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
2148     space and tab.
2149    
2150     6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
2151     its new features into the main test script, reducing the number of scripts.
2152    
2153     7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
2154     were backward compatible, and made the (?i) apply to the whole pattern, as if
2155     /i were given. Now it behaves more logically, and applies the option setting
2156     only to what follows. PCRE has been changed to follow suit. However, if it
2157     finds options settings right at the start of the pattern, it extracts them into
2158     the global options, as before. Thus, they show up in the info data.
2159    
2160     8. Added support for the \Q...\E escape sequence. Characters in between are
2161     treated as literals. This is slightly different from Perl in that $ and @ are
2162     also handled as literals inside the quotes. In Perl, they will cause variable
2163     interpolation. Note the following examples:
2164    
2165     Pattern PCRE matches Perl matches
2166    
2167     \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
2168     \Qabc\$xyz\E abc\$xyz abc\$xyz
2169     \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
2170    
2171     For compatibility with Perl, \Q...\E sequences are recognized inside character
2172     classes as well as outside them.
2173    
2174     9. Re-organized 3 code statements in pcretest to avoid "overflow in
2175     floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
2176     (size_t) cast to one statement in pcretest and one in pcreposix to avoid
2177     signed/unsigned warnings.
2178    
2179     10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
2180     option for pcretest, so I've replaced it by a simple function that does just
2181     that job.
2182    
2183     11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
2184     "pcregrep -".
2185    
2186     12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
2187     Java package. This provides some syntactic sugar for simple cases of what my
2188     documentation calls "once-only subpatterns". A pattern such as x*+ is the same
2189     as (?>x*). In other words, if what is inside (?>...) is just a single repeated
2190     item, you can use this simplified notation. Note that only makes sense with
2191     greedy quantifiers. Consequently, the use of the possessive quantifier forces
2192     greediness, whatever the setting of the PCRE_UNGREEDY option.
2193    
2194     13. A change of greediness default within a pattern was not taking effect at
2195     the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
2196     subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
2197     was abstracted outside.
2198    
2199     14. PCRE now supports the \G assertion. It is true when the current matching
2200     position is at the start point of the match. This differs from \A when the
2201     starting offset is non-zero. Used with the /g option of pcretest (or similar
2202     code), it works in the same way as it does for Perl's /g option. If all
2203     alternatives of a regex begin with \G, the expression is anchored to the start
2204     match position, and the "anchored" flag is set in the compiled expression.
2205    
2206     15. Some bugs concerning the handling of certain option changes within patterns
2207     have been fixed. These applied to options other than (?ims). For example,
2208     "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
2209     been the other way round. Some of this was related to change 7 above.
2210    
2211     16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
2212     features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
2213     and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
2214     POSIX classes only within a class (e.g. /[[:alpha:]]/).
2215    
2216     17. Added support for Perl's \C escape. This matches one byte, even in UTF8
2217     mode. Unlike ".", it always matches newline, whatever the setting of
2218     PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
2219     assertions. Perl allows it, but it doesn't (in general) work because it can't
2220     calculate the length of the lookbehind. At least, that's the case for Perl
2221     5.8.0 - I've been told they are going to document that it doesn't work in
2222     future.
2223    
2224     18. Added an error diagnosis for escapes that PCRE does not support: these are
2225     \L, \l, \N, \P, \p, \U, \u, and \X.
2226    
2227     19. Although correctly diagnosing a missing ']' in a character class, PCRE was
2228     reading past the end of the pattern in cases such as /[abcd/.
2229    
2230     20. PCRE was getting more memory than necessary for patterns with classes that
2231     contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
2232    
2233     21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
2234     compiling PCRE for use with Virtual Pascal.
2235    
2236     22. Small fix to the Makefile to make it work properly if the build is done
2237     outside the source tree.
2238    
2239     23. Added a new extension: a condition to go with recursion. If a conditional
2240     subpattern starts with (?(R) the "true" branch is used if recursion has
2241     happened, whereas the "false" branch is used only at the top level.
2242    
2243     24. When there was a very long string of literal characters (over 255 bytes
2244     without UTF support, over 250 bytes with UTF support), the computation of how
2245     much memory was required could be incorrect, leading to segfaults or other
2246     strange effects.
2247    
2248     25. PCRE was incorrectly assuming anchoring (either to start of subject or to
2249     start of line for a non-DOTALL pattern) when a pattern started with (.*) and
2250     there was a subsequent back reference to those brackets. This meant that, for
2251     example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
2252     possible to check for precisely this case. All we can do is abandon the
2253     optimization if .* occurs inside capturing brackets when there are any back
2254     references whatsoever. (See below for a better fix that came later.)
2255    
2256     26. The handling of the optimization for finding the first character of a
2257     non-anchored pattern, and for finding a character that is required later in the
2258     match were failing in some cases. This didn't break the matching; it just
2259     failed to optimize when it could. The way this is done has been re-implemented.
2260    
2261     27. Fixed typo in error message for invalid (?R item (it said "(?p").
2262    
2263     28. Added a new feature that provides some of the functionality that Perl
2264     provides with (?{...}). The facility is termed a "callout". The way it is done
2265     in PCRE is for the caller to provide an optional function, by setting
2266     pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
2267     global variable. By default it is unset, which disables all calling out. To get
2268     the function called, the regex must include (?C) at appropriate points. This
2269     is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
2270     This provides a means of identifying different callout points. When PCRE
2271     reaches such a point in the regex, if pcre_callout has been set, the external
2272     function is called. It is provided with data in a structure called
2273     pcre_callout_block, which is defined in pcre.h. If the function returns 0,
2274     matching continues; if it returns a non-zero value, the match at the current
2275     point fails. However, backtracking will occur if possible. [This was changed
2276     later and other features added - see item 49 below.]
2277    
2278     29. pcretest is upgraded to test the callout functionality. It provides a
2279     callout function that displays information. By default, it shows the start of
2280     the match and the current position in the text. There are some new data escapes
2281     to vary what happens:
2282    
2283     \C+ in addition, show current contents of captured substrings
2284     \C- do not supply a callout function
2285     \C!n return 1 when callout number n is reached
2286     \C!n!m return 1 when callout number n is reached for the mth time
2287    
2288     30. If pcregrep was called with the -l option and just a single file name, it
2289     output "<stdin>" if a match was found, instead of the file name.
2290    
2291     31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
2292     slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
2293     pcre_exec(). This saves a malloc/free per call. The default value of
2294     POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
2295     when configuring.
2296    
2297     32. The default maximum size of a compiled pattern is 64K. There have been a
2298     few cases of people hitting this limit. The code now uses macros to handle the
2299     storing of links as offsets within the compiled pattern. It defaults to 2-byte
2300     links, but this can be changed to 3 or 4 bytes by --with-link-size when
2301     configuring. Tests 2 and 5 work only with 2-byte links because they output
2302     debugging information about compiled patterns.
2303    
2304     33. Internal code re-arrangements:
2305    
2306     (a) Moved the debugging function for printing out a compiled regex into
2307     its own source file (printint.c) and used #include to pull it into
2308     pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
2309     separate copies.
2310    
2311     (b) Defined the list of op-code names for debugging as a macro in
2312     internal.h so that it is next to the definition of the opcodes.
2313    
2314     (c) Defined a table of op-code lengths for simpler skipping along compiled
2315     code. This is again a macro in internal.h so that it is next to the
2316     definition of the opcodes.
2317    
2318     34. Added support for recursive calls to individual subpatterns, along the
2319     lines of Robin Houston's patch (but implemented somewhat differently).
2320    
2321     35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
2322     allow it to read and process whole directories in Win32. This code was
2323     contributed by Lionel Fourquaux; it has not been tested by me.
2324    
2325     36. Added support for named subpatterns. The Python syntax (?P<name>...) is
2326     used to name a group. Names consist of alphanumerics and underscores, and must
2327     be unique. Back references use the syntax (?P=name) and recursive calls use
2328     (?P>name) which is a PCRE extension to the Python extension. Groups still have
2329     numbers. The function pcre_fullinfo() can be used after compilation to extract
2330     a name/number map. There are three relevant calls:
2331    
2332     PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
2333     PCRE_INFO_NAMECOUNT yields the number of entries
2334     PCRE_INFO_NAMETABLE yields a pointer to the map.
2335    
2336     The map is a vector of fixed-size entries. The size of each entry depends on
2337     the length of the longest name used. The first two bytes of each entry are the
2338     group number, most significant byte first. There follows the corresponding
2339     name, zero terminated. The names are in alphabetical order.
2340    
2341     37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
2342     case instead of 255. Making it the same both with and without UTF-8 support
2343     means that the same test output works with both.
2344    
2345     38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
2346     calling malloc() with a zero argument.
2347    
2348     39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
2349     optimization. I've improved things by keeping a bitmap of backreferences with
2350     numbers 1-31 so that if .* occurs inside capturing brackets that are not in
2351     fact referenced, the optimization can be applied. It is unlikely that a
2352     relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
2353     the match to follow \n) will appear inside brackets with a number greater than
2354     31, but if it does, any back reference > 31 suppresses the optimization.
2355    
2356     40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
2357     of disabling numbered capturing parentheses. Any opening parenthesis that is
2358     not followed by ? behaves as if it were followed by ?: but named parentheses
2359     can still be used for capturing (and they will acquire numbers in the usual
2360     way).
2361    
2362     41. Redesigned the return codes from the match() function into yes/no/error so
2363     that errors can be passed back from deep inside the nested calls. A malloc
2364     failure while inside a recursive subpattern call now causes the
2365     PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
2366    
2367     42. It is now possible to set a limit on the number of times the match()
2368     function is called in a call to pcre_exec(). This facility makes it possible to
2369     limit the amount of recursion and backtracking, though not in a directly
2370     obvious way, because the match() function is used in a number of different
2371     circumstances. The count starts from zero for each position in the subject
2372     string (for non-anchored patterns). The default limit is, for compatibility, a
2373     large number, namely 10 000 000. You can change this in two ways:
2374    
2375     (a) When configuring PCRE before making, you can use --with-match-limit=n
2376     to set a default value for the compiled library.
2377    
2378     (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
2379     a different value is set. See 45 below.
2380    
2381     If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
2382    
2383     43. Added a new function pcre_config(int, void *) to enable run-time extraction
2384     of things that can be changed at compile time. The first argument specifies
2385     what is wanted and the second points to where the information is to be placed.
2386     The current list of available information is:
2387    
2388     PCRE_CONFIG_UTF8
2389    
2390     The output is an integer that is set to one if UTF-8 support is available;
2391     otherwise it is set to zero.
2392    
2393     PCRE_CONFIG_NEWLINE
2394    
2395     The output is an integer that it set to the value of the code that is used for
2396     newline. It is either LF (10) or CR (13).
2397    
2398     PCRE_CONFIG_LINK_SIZE
2399    
2400     The output is an integer that contains the number of bytes used for internal
2401     linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
2402    
2403     PCRE_CONFIG_POSIX_MALLOC_THRESHOLD
2404    
2405     The output is an integer that contains the threshold above which the POSIX
2406     interface uses malloc() for output vectors. See item 31 above.
2407    
2408     PCRE_CONFIG_MATCH_LIMIT
2409    
2410     The output is an unsigned integer that contains the default limit of the number
2411     of match() calls in a pcre_exec() execution. See 42 above.
2412    
2413     44. pcretest has been upgraded by the addition of the -C option. This causes it
2414     to extract all the available output from the new pcre_config() function, and to
2415     output it. The program then exits immediately.
2416    
2417     45. A need has arisen to pass over additional data with calls to pcre_exec() in
2418     order to support additional features. One way would have been to define
2419     pcre_exec2() (for example) with extra arguments, but this would not have been
2420     extensible, and would also have required all calls to the original function to
2421     be mapped to the new one. Instead, I have chosen to extend the mechanism that
2422     is used for passing in "extra" data from pcre_study().
2423    
2424     The pcre_extra structure is now exposed and defined in pcre.h. It currently
2425     contains the following fields:
2426    
2427     flags a bitmap indicating which of the following fields are set
2428     study_data opaque data from pcre_study()
2429     match_limit a way of specifying a limit on match() calls for a specific
2430     call to pcre_exec()
2431     callout_data data for callouts (see 49 below)
2432    
2433     The flag bits are also defined in pcre.h, and are
2434    
2435     PCRE_EXTRA_STUDY_DATA
2436     PCRE_EXTRA_MATCH_LIMIT
2437     PCRE_EXTRA_CALLOUT_DATA
2438    
2439     The pcre_study() function now returns one of these new pcre_extra blocks, with
2440     the actual study data pointed to by the study_data field, and the
2441     PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
2442     before. That is, this change is entirely upwards-compatible and requires no
2443     change to existing code.
2444    
2445     If you want to pass in additional data to pcre_exec(), you can either place it
2446     in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
2447     block.
2448    
2449     46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
2450     data string contains the escape sequence \M, pcretest calls pcre_exec() several
2451     times with different match limits, until it finds the minimum value needed for
2452     pcre_exec() to complete. The value is then output. This can be instructive; for
2453     most simple matches the number is quite small, but for pathological cases it
2454     gets very large very quickly.
2455    
2456     47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
2457     returns the size of the data block pointed to by the study_data field in a
2458     pcre_extra block, that is, the value that was passed as the argument to
2459     pcre_malloc() when PCRE was getting memory in which to place the information
2460     created by pcre_study(). The fourth argument should point to a size_t variable.
2461     pcretest has been extended so that this information is shown after a successful
2462     pcre_study() call when information about the compiled regex is being displayed.
2463    
2464     48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
2465     because what follows is always an absolute path. (Later: it turns out that this
2466     is more than cosmetic for MinGW, because it doesn't like empty path
2467     components.)
2468    
2469     49. Some changes have been made to the callout feature (see 28 above):
2470    
2471     (i) A callout function now has three choices for what it returns:
2472    
2473     0 => success, carry on matching
2474     > 0 => failure at this point, but backtrack if possible
2475     < 0 => serious error, return this value from pcre_exec()
2476    
2477     Negative values should normally be chosen from the set of PCRE_ERROR_xxx
2478     values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
2479     "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
2480     use by callout functions. It will never be used by PCRE itself.
2481    
2482     (ii) The pcre_extra structure (see 45 above) has a void * field called
2483     callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
2484     pcre_callout_block structure has a field of the same name. The contents of
2485     the field passed in the pcre_extra structure are passed to the callout
2486     function in the corresponding field in the callout block. This makes it
2487     easier to use the same callout-containing regex from multiple threads. For
2488     testing, the pcretest program has a new data escape
2489    
2490     \C*n pass the number n (may be negative) as callout_data
2491    
2492     If the callout function in pcretest receives a non-zero value as
2493     callout_data, it returns that value.
2494    
2495     50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
2496     there were some redundant $(CFLAGS) in commands that are now specified as
2497     $(LINK), which already includes $(CFLAGS).
2498    
2499     51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
2500     has been compiled with UTF-8 support *and* pcre_compile() has been compiled
2501     with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
2502     one-byte characters throughout. Note that case-insensitive matching applies
2503     only to characters whose values are less than 256. PCRE doesn't support the
2504     notion of cases for higher-valued characters.
2505    
2506     (i) A character class whose characters are all within 0-255 is handled as
2507     a bit map, and the map is inverted for negative classes. Previously, a
2508     character > 255 always failed to match such a class; however it should
2509     match if the class was a negative one (e.g. [^ab]). This has been fixed.
2510    
2511     (ii) A negated character class with a single character < 255 is coded as
2512     "not this character" (OP_NOT). This wasn't working properly when the test
2513     character was multibyte, either singly or repeated.
2514    
2515     (iii) Repeats of multibyte characters are now handled correctly in UTF-8
2516     mode, for example: \x{100}{2,3}.
2517    
2518     (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
2519     singly or repeated) now correctly test multibyte characters. However,
2520     PCRE doesn't recognize any characters with values greater than 255 as
2521     digits, spaces, or word characters. Such characters always match \D, \S,
2522     and \W, and never match \d, \s, or \w.
2523    
2524     (v) Classes may now contain characters and character ranges with values
2525     greater than 255. For example: [ab\x{100}-\x{400}].
2526    
2527     (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
2528     PCRE in UTF-8 mode.
2529    
2530     52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
2531     PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
2532     retained for backwards compatibility. (Note that LASTLITERAL is also a byte
2533     value.)
2534    
2535     53. The single man page has become too large. I have therefore split it up into
2536     a number of separate man pages. These also give rise to individual HTML pages;
2537     these are now put in a separate directory, and there is an index.html page that
2538     lists them all. Some hyperlinking between the pages has been installed.
2539    
2540     54. Added convenience functions for handling named capturing parentheses.
2541    
2542     55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
2543     aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
2544     true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
2545     are faulted.
2546    
2547     56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
2548     calling configure. These values are used when compiling the dftables.c program
2549     which is run to generate the source of the default character tables. They
2550     default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
2551     you will need to set these values.
2552    
2553     57. Updated the building process for Windows DLL, as provided by Fred Cox.
2554    
2555    
2556     Version 3.9 02-Jan-02
2557 nigel 61 ---------------------
2558    
2559     1. A bit of extraneous text had somehow crept into the pcregrep documentation.
2560    
2561     2. If --disable-static was given, the building process failed when trying to
2562     build pcretest and pcregrep. (For some reason it was using libtool to compile
2563     them, which is not right, as they aren't part of the library.)
2564    
2565    
2566 nigel 59 Version 3.8 18-Dec-01
2567     ---------------------
2568    
2569     1. The experimental UTF-8 code was completely screwed up. It was packing the
2570     bytes in the wrong order. How dumb can you get?
2571    
2572    
2573 nigel 57 Version 3.7 29-Oct-01
2574     ---------------------
2575    
2576     1. In updating pcretest to check change 1 of version 3.6, I screwed up.
2577     This caused pcretest, when used on the test data, to segfault. Unfortunately,
2578     this didn't happen under Solaris 8, where I normally test things.
2579    
2580 nigel 59 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
2581     doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
2582     isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
2583     this fix an hour or so after the initial 3.7 release.)
2584 nigel 57
2585 nigel 59
2586 nigel 55 Version 3.6 23-Oct-01
2587     ---------------------
2588    
2589     1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
2590     offsets passed as NULL with zero offset count.
2591    
2592     2. The config.guess and config.sub files had not been updated when I moved to
2593     the latest autoconf.
2594    
2595    
2596 nigel 53 Version 3.5 15-Aug-01
2597     ---------------------
2598 nigel 5
2599 nigel 53 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
2600     had been forgotten.
2601    
2602     2. By using declared but undefined structures, we can avoid using "void"
2603     definitions in pcre.h while keeping the internal definitions of the structures
2604     private.
2605    
2606     3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
2607     user point of view, this means that both static and shared libraries are built
2608     by default, but this can be individually controlled. More of the work of
2609     handling this static/shared cases is now inside libtool instead of PCRE's make
2610     file.
2611    
2612     4. The pcretest utility is now installed along with pcregrep because it is
2613     useful for users (to test regexs) and by doing this, it automatically gets
2614     relinked by libtool. The documentation has been turned into a man page, so
2615     there are now .1, .txt, and .html versions in /doc.
2616    
2617     5. Upgrades to pcregrep:
2618     (i) Added long-form option names like gnu grep.
2619     (ii) Added --help to list all options with an explanatory phrase.
2620     (iii) Added -r, --recursive to recurse into sub-directories.
2621     (iv) Added -f, --file to read patterns from a file.
2622    
2623     6. pcre_exec() was referring to its "code" argument before testing that
2624     argument for NULL (and giving an error if it was NULL).
2625    
2626     7. Upgraded Makefile.in to allow for compiling in a different directory from
2627     the source directory.
2628    
2629     8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
2630     options bits, the pointer it was passed was to an int instead of to an unsigned
2631     long int. This mattered only on 64-bit systems.
2632    
2633     9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
2634     generated) instead of pcre.in, which it its source. Also made the same change
2635     in several of the .c files.
2636    
2637     10. A new release of gcc defines printf() as a macro, which broke pcretest
2638     because it had an ifdef in the middle of a string argument for printf(). Fixed
2639     by using separate calls to printf().
2640    
2641     11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
2642     script, to force use of CR or LF instead of \n in the source. On non-Unix
2643     systems, the value can be set in config.h.
2644    
2645     12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
2646     absolute limit. Changed the text of the error message to make this clear, and
2647     likewise updated the man page.
2648    
2649     13. The limit of 99 on the number of capturing subpatterns has been removed.
2650     The new limit is 65535, which I hope will not be a "real" limit.
2651    
2652    
2653 nigel 51 Version 3.4 22-Aug-00
2654     ---------------------
2655    
2656     1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
2657    
2658     2. Diagnose condition (?(0) as an error instead of crashing on matching.
2659    
2660    
2661 nigel 49 Version 3.3 01-Aug-00
2662     ---------------------
2663    
2664     1. If an octal character was given, but the value was greater than \377, it
2665     was not getting masked to the least significant bits, as documented. This could
2666     lead to crashes in some systems.
2667    
2668     2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
2669     the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
2670    
2671     3. Added the functions pcre_free_substring() and pcre_free_substring_list().
2672     These just pass their arguments on to (pcre_free)(), but they are provided
2673     because some uses of PCRE bind it to non-C systems that can call its functions,
2674     but cannot call free() or pcre_free() directly.
2675    
2676     4. Add "make test" as a synonym for "make check". Corrected some comments in
2677     the Makefile.
2678    
2679     5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
2680     Makefile.
2681    
2682     6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
2683     command called pgrep for grepping around the active processes.
2684    
2685     7. Added the beginnings of support for UTF-8 character strings.
2686    
2687     8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
2688     RANLIB to ./ltconfig so that they are used by libtool. I think these are all
2689     the relevant ones. (AR is not passed because ./ltconfig does its own figuring
2690     out for the ar command.)
2691    
2692    
2693 nigel 47 Version 3.2 12-May-00
2694     ---------------------
2695    
2696     This is purely a bug fixing release.
2697    
2698     1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
2699     of ZA. This was just one example of several cases that could provoke this bug,
2700     which was introduced by change 9 of version 2.00. The code for breaking
2701     infinite loops after an iteration that matches an empty string was't working
2702     correctly.
2703    
2704     2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
2705     when matched against abbab (for example). After matching an empty string, it
2706     wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
2707     caused it to match further down the string than it should.
2708    
2709     3. The code contained an inclusion of sys/types.h. It isn't clear why this
2710     was there because it doesn't seem to be needed, and it causes trouble on some
2711     systems, as it is not a Standard C header. It has been removed.
2712    
2713     4. Made 4 silly changes to the source to avoid stupid compiler warnings that
2714     were reported on the Macintosh. The changes were from
2715    
2716     while ((c = *(++ptr)) != 0 && c != '\n');
2717     to
2718     while ((c = *(++ptr)) != 0 && c != '\n') ;
2719    
2720     Totally extraordinary, but if that's what it takes...
2721    
2722     5. PCRE is being used in one environment where neither memmove() nor bcopy() is
2723     available. Added HAVE_BCOPY and an autoconf test for it; if neither
2724     HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
2725     assumes the way PCRE uses memmove() (always moving upwards).
2726    
2727     6. PCRE is being used in one environment where strchr() is not available. There
2728     was only one use in pcre.c, and writing it out to avoid strchr() probably gives
2729     faster code anyway.
2730    
2731    
2732 nigel 45 Version 3.1 09-Feb-00
2733     ---------------------
2734    
2735     The only change in this release is the fixing of some bugs in Makefile.in for
2736     the "install" target:
2737    
2738     (1) It was failing to install pcreposix.h.
2739    
2740     (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
2741    
2742    
2743 nigel 43 Version 3.0 01-Feb-00
2744     ---------------------
2745 nigel 41
2746     1. Add support for the /+ modifier to perltest (to output $` like it does in
2747     pcretest).
2748    
2749     2. Add support for the /g modifier to perltest.
2750    
2751     3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
2752     matches null strings.
2753    
2754     4. Fix perltest so that it doesn't do unwanted things when fed an empty
2755     pattern. Perl treats empty patterns specially - it reuses the most recent
2756     pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
2757     effect.
2758    
2759     5. The POSIX interface was broken in that it was just handing over the POSIX
2760     captured string vector to pcre_exec(), but (since release 2.00) PCRE has
2761     required a bigger vector, with some working space on the end. This means that
2762     the POSIX wrapper now has to get and free some memory, and copy the results.
2763    
2764 nigel 43 6. Added some simple autoconf support, placing the test data and the
2765     documentation in separate directories, re-organizing some of the
2766     information files, and making it build pcre-config (a GNU standard). Also added
2767     libtool support for building PCRE as a shared library, which is now the
2768     default.
2769 nigel 41
2770 nigel 43 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
2771     09 are not valid octal constants. Single digits will be used for minor values
2772     less than 10.
2773    
2774     8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
2775     existing programs that set these in the POSIX interface can use PCRE without
2776     modification.
2777    
2778     9. Added a new function, pcre_fullinfo() with an extensible interface. It can
2779     return all that pcre_info() returns, plus additional data. The pcre_info()
2780     function is retained for compatibility, but is considered to be obsolete.
2781    
2782     10. Added experimental recursion feature (?R) to handle one common case that
2783     Perl 5.6 will be able to do with (?p{...}).
2784    
2785     11. Added support for POSIX character classes like [:alpha:], which Perl is
2786     adopting.
2787    
2788    
2789 nigel 39 Version 2.08 31-Aug-99
2790     ----------------------
2791    
2792     1. When startoffset was not zero and the pattern began with ".*", PCRE was not
2793     trying to match at the startoffset position, but instead was moving forward to
2794     the next newline as if a previous match had failed.
2795    
2796     2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
2797     and could get into a loop if a null string was matched other than at the start
2798     of the subject.
2799    
2800     3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
2801     be distinguished at compile time, and for completeness also added PCRE_DATE.
2802    
2803     5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
2804     in GnuWin32 environments.
2805    
2806    
2807 nigel 37 Version 2.07 29-Jul-99
2808     ----------------------
2809    
2810     1. The documentation is now supplied in plain text form and HTML as well as in
2811     the form of man page sources.
2812    
2813     2. C++ compilers don't like assigning (void *) values to other pointer types.
2814     In particular this affects malloc(). Although there is no problem in Standard
2815     C, I've put in casts to keep C++ compilers happy.
2816    
2817     3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
2818     should be (const char *).
2819    
2820     4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
2821     be useful for non-Unix systems who don't want to bother with the POSIX stuff.
2822     However, I haven't made this a standard facility. The documentation doesn't
2823     mention it, and the Makefile doesn't support it.
2824    
2825     5. The Makefile now contains an "install" target, with editable destinations at
2826     the top of the file. The pcretest program is not installed.
2827    
2828     6. pgrep -V now gives the PCRE version number and date.
2829    
2830     7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
2831     causing the entire string to be ignored, instead of just the last character.
2832    
2833     8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
2834     non-matching string, it can take a very, very long time, even for strings of
2835     quite modest length, because of the nested recursion. PCRE now does better in
2836     some of these cases. It does this by remembering the last required literal
2837     character in the pattern, and pre-searching the subject to ensure it is present
2838     before running the real match. In other words, it applies a heuristic to detect
2839     some types of certain failure quickly, and in the above example, if presented
2840     with a string that has no trailing " it gives "no match" very quickly.
2841    
2842     9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
2843     other alternatives are tried instead.
2844    
2845    
2846 nigel 35 Version 2.06 09-Jun-99
2847     ----------------------
2848    
2849     1. Change pcretest's output for amount of store used to show just the code
2850     space, because the remainder (the data block) varies in size between 32-bit and
2851     64-bit systems.
2852    
2853     2. Added an extra argument to pcre_exec() to supply an offset in the subject to
2854     start matching at. This allows lookbehinds to work when searching for multiple
2855     occurrences in a string.
2856    
2857     3. Added additional options to pcretest for testing multiple occurrences:
2858    
2859     /+ outputs the rest of the string that follows a match
2860     /g loops for multiple occurrences, using the new startoffset argument
2861     /G loops for multiple occurrences by passing an incremented pointer
2862    
2863     4. PCRE wasn't doing the "first character" optimization for patterns starting
2864     with \b or \B, though it was doing it for other lookbehind assertions. That is,
2865     it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
2866     the letter 'x'. On long subject strings, this gives a significant speed-up.
2867    
2868    
2869 nigel 33 Version 2.05 21-Apr-99
2870     ----------------------
2871    
2872     1. Changed the type of magic_number from int to long int so that it works
2873     properly on 16-bit systems.
2874    
2875     2. Fixed a bug which caused patterns starting with .* not to work correctly
2876     when the subject string contained newline characters. PCRE was assuming
2877     anchoring for such patterns in all cases, which is not correct because .* will
2878     not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
2879     DOTALL is set at top level; otherwise it knows that patterns starting with .*
2880     must be retried after every newline in the subject.
2881    
2882    
2883 nigel 31 Version 2.04 18-Feb-99
2884     ----------------------
2885    
2886     1. For parenthesized subpatterns with repeats whose minimum was zero, the
2887     computation of the store needed to hold the pattern was incorrect (too large).
2888     If such patterns were nested a few deep, this could multiply and become a real
2889     problem.
2890    
2891     2. Added /M option to pcretest to show the memory requirement of a specific
2892     pattern. Made -m a synonym of -s (which does this globally) for compatibility.
2893    
2894     3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
2895     compiled in such a way that the backtracking after subsequent failure was
2896     pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
2897     ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
2898    
2899    
2900 nigel 29 Version 2.03 02-Feb-99
2901     ----------------------
2902    
2903     1. Fixed typo and small mistake in man page.
2904    
2905 nigel 31 2. Added 4th condition (GPL supersedes if conflict) and created separate
2906     LICENCE file containing the conditions.
2907 nigel 29
2908     3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
2909     Perl, that is the internal \ allows the delimiter to be included in the
2910     pattern. Locked out the use of \ as a delimiter. If \ immediately follows
2911     the final delimiter, add \ to the end of the pattern (to test the error).
2912    
2913     4. Added the convenience functions for extracting substrings after a successful
2914     match. Updated pcretest to make it able to test these functions.
2915    
2916    
2917 nigel 27 Version 2.02 14-Jan-99
2918     ----------------------
2919    
2920     1. Initialized the working variables associated with each extraction so that
2921     their saving and restoring doesn't refer to uninitialized store.
2922    
2923     2. Put dummy code into study.c in order to trick the optimizer of the IBM C
2924     compiler for OS/2 into generating correct code. Apparently IBM isn't going to
2925     fix the problem.
2926    
2927     3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
2928     calls, and wasn't printing the correct value for compiling calls. Increased the
2929     default value of LOOPREPEAT, and the number of significant figures in the
2930     times.
2931    
2932     4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
2933    
2934     5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
2935     a building problem on Windows NT with a FAT file system.
2936    
2937    
2938 nigel 25 Version 2.01 21-Oct-98
2939     ----------------------
2940    
2941     1. Changed the API for pcre_compile() to allow for the provision of a pointer
2942     to character tables built by pcre_maketables() in the current locale. If NULL
2943     is passed, the default tables are used.
2944    
2945    
2946 nigel 23 Version 2.00 24-Sep-98
2947 nigel 21 ----------------------
2948    
2949 nigel 23 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
2950     it any more.
2951    
2952     2. Allow quantification of (?>) groups, and make it work correctly.
2953    
2954     3. The first character computation wasn't working for (?>) groups.
2955    
2956     4. Correct the implementation of \Z (it is permitted to match on the \n at the
2957     end of the subject) and add 5.005's \z, which really does match only at the
2958     very end of the subject.
2959    
2960     5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
2961    
2962     6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
2963     DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
2964     localized options. All options to pcre_study() were also removed.
2965    
2966     7. Add other new features from 5.005:
2967    
2968     $(?<= positive lookbehind
2969     $(?<! negative lookbehind
2970     (?imsx-imsx) added the unsetting capability
2971     such a setting is global if at outer level; local otherwise
2972     (?imsx-imsx:) non-capturing groups with option setting
2973     (?(cond)re|re) conditional pattern matching
2974    
2975     A backreference to itself in a repeated group matches the previous
2976     captured string.
2977    
2978     8. General tidying up of studying (both automatic and via "study")
2979     consequential on the addition of new assertions.
2980    
2981     9. As in 5.005, unlimited repeated groups that could match an empty substring
2982     are no longer faulted at compile time. Instead, the loop is forcibly broken at
2983     runtime if any iteration does actually match an empty substring.
2984    
2985     10. Include the RunTest script in the distribution.
2986    
2987     11. Added tests from the Perl 5.005_02 distribution. This showed up a few
2988     discrepancies, some of which were old and were also with respect to 5.004. They
2989     have now been fixed.
2990    
2991    
2992     Version 1.09 28-Apr-98
2993     ----------------------
2994    
2995 nigel 21 1. A negated single character class followed by a quantifier with a minimum
2996     value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
2997     program crashes, or just wrong answers. This did not apply to negated classes
2998     containing more than one character, or to minima other than one.
2999    
3000    
3001 nigel 19 Version 1.08 27-Mar-98
3002     ----------------------
3003    
3004     1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
3005    
3006     2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
3007     latter must appear before anything that relies on it in the pattern.
3008    
3009    
3010 nigel 17 Version 1.07 16-Feb-98
3011     ----------------------
3012    
3013     1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
3014     repeat of a potentially empty string).
3015    
3016    
3017 nigel 15 Version 1.06 23-Jan-98
3018     ----------------------
3019    
3020     1. Added Markus Oberhumer's little patches for C++.
3021    
3022     2. Literal strings longer than 255 characters were broken.
3023    
3024    
3025 nigel 13 Version 1.05 23-Dec-97
3026     ----------------------
3027    
3028     1. Negated character classes containing more than one character were failing if
3029     PCRE_CASELESS was set at run time.
3030    
3031    
3032 nigel 11 Version 1.04 19-Dec-97
3033     ----------------------
3034    
3035     1. Corrected the man page, where some "const" qualifiers had been omitted.
3036    
3037     2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
3038     input syntax.
3039    
3040     3. Fixed memory leak which occurred when a regex with back references was
3041     matched with an offsets vector that wasn't big enough. The temporary memory
3042     that is used in this case wasn't being freed if the match failed.
3043    
3044     4. Tidied pcretest to ensure it frees memory that it gets.
3045    
3046     5. Temporary memory was being obtained in the case where the passed offsets
3047     vector was exactly big enough.
3048    
3049     6. Corrected definition of offsetof() from change 5 below.
3050    
3051     7. I had screwed up change 6 below and broken the rules for the use of
3052     setjmp(). Now fixed.
3053    
3054    
3055 nigel 9 Version 1.03 18-Dec-97
3056     ----------------------
3057    
3058     1. A erroneous regex with a missing opening parenthesis was correctly
3059     diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
3060     on some systems.
3061    
3062     2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
3063     it was reported that one broken compiler failed on the former because "code" is
3064     also an independent variable.
3065    
3066     3. The erroneous regex a[]b caused an array overrun reference.
3067    
3068     4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
3069     fail on data ending with that character. (It was going on too far, and checking
3070     the next character, typically a binary zero.) This was specific to the
3071     optimized code for single-character negative classes.
3072    
3073     5. Added a contributed patch from the TIN world which does the following:
3074    
3075     + Add an undef for memmove, in case the the system defines a macro for it.
3076    
3077     + Add a definition of offsetof(), in case there isn't one. (I don't know
3078     the reason behind this - offsetof() is part of the ANSI standard - but
3079     it does no harm).
3080    
3081     + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
3082     most of the places where whitespace preceded '#'. I have given up and
3083     allowed the remaining 2 cases to be at the margin.
3084    
3085     + Rename some variables in pcre to eliminate shadowing. This seems very
3086     pedantic, but does no harm, of course.
3087    
3088     6. Moved the call to setjmp() into its own function, to get rid of warnings
3089     from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
3090    
3091     7. Constructs such as \d{8,} were compiling into the equivalent of
3092 nigel 11 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
3093 nigel 9 outcome, but in this particular case used more store than had been allocated,
3094     which caused the bug to be discovered because it threw up an internal error.
3095    
3096     8. The debugging code in both pcre and pcretest for outputting the compiled
3097     form of a regex was going wrong in the case of back references followed by
3098     curly-bracketed repeats.
3099    
3100    
3101 nigel 7 Version 1.02 12-Dec-97
3102     ----------------------
3103    
3104     1. Typos in pcre.3 and comments in the source fixed.
3105    
3106     2. Applied a contributed patch to get rid of places where it used to remove
3107     'const' from variables, and fixed some signed/unsigned and uninitialized
3108     variable warnings.
3109    
3110     3. Added the "runtest" target to Makefile.
3111    
3112     4. Set default compiler flag to -O2 rather than just -O.
3113    
3114    
3115 nigel 5 Version 1.01 19-Nov-97
3116     ----------------------
3117    
3118     1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
3119     like /([ab]*)*/, that is, for classes with more than one character in them.
3120    
3121     2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
3122     as /((?>a*))*/ (a PCRE_EXTRA facility).
3123    
3124    
3125     Version 1.00 18-Nov-97
3126     ----------------------
3127    
3128     1. Added compile-time macros to support systems such as SunOS4 which don't have
3129     memmove() or strerror() but have other things that can be used instead.
3130    
3131     2. Arranged that "make clean" removes the executables.
3132    
3133    
3134 nigel 3 Version 0.99 27-Oct-97
3135     ----------------------
3136    
3137     1. Fixed bug in code for optimizing classes with only one character. It was
3138     initializing a 32-byte map regardless, which could cause it to run off the end
3139     of the memory it had got.
3140    
3141     2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
3142    
3143    
3144     Version 0.98 22-Oct-97
3145     ----------------------
3146    
3147     1. Fixed bug in code for handling temporary memory usage when there are more
3148     back references than supplied space in the ovector. This could cause segfaults.
3149    
3150    
3151     Version 0.97 21-Oct-97
3152     ----------------------
3153    
3154     1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
3155    
3156     2. Optimized negated single characters not to use a bit map.
3157    
3158     3. Brought error texts together as macro definitions; clarified some of them;
3159     fixed one that was wrong - it said "range out of order" when it meant "invalid
3160     escape sequence".
3161    
3162     4. Changed some char * arguments to const char *.
3163    
3164     5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
3165    
3166     6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
3167     pcretest.
3168    
3169    
3170     Version 0.96 16-Oct-97
3171     ----------------------
3172    
3173     1. Added a simple "pgrep" utility to the distribution.
3174    
3175     2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
3176     unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
3177     where "ddd" means "one or more decimal digits".
3178    
3179     3. Fixed serious bug. If a pattern had a back reference, but the call to
3180     pcre_exec() didn't supply a large enough ovector to record the related
3181     identifying subpattern, the match always failed. PCRE now remembers the number
3182     of the largest back reference, and gets some temporary memory in which to save
3183     the offsets during matching if necessary, in order to ensure that
3184     backreferences always work.
3185    
3186     4. Increased the compatibility with Perl in a number of ways:
3187    
3188     (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
3189     to request this handling. The option can be set at compile or exec time.
3190    
3191     (b) $ matches before a terminating newline by default; an option
3192     PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
3193     mode). The option can be set at compile or exec time.
3194    
3195     (c) The handling of \ followed by a digit other than 0 is now supposed to be
3196     the same as Perl's. If the decimal number it represents is less than 10
3197     or there aren't that many previous left capturing parentheses, an octal
3198     escape is read. Inside a character class, it's always an octal escape,
3199     even if it is a single digit.
3200    
3201     (d) An escaped but undefined alphabetic character is taken as a literal,
3202     unless PCRE_EXTRA is set. Currently this just reserves the remaining
3203     escapes.
3204    
3205     (e) {0} is now permitted. (The previous item is removed from the compiled
3206     pattern).
3207    
3208     5. Changed all the names of code files so that the basic parts are no longer
3209     than 10 characters, and abolished the teeny "globals.c" file.
3210    
3211     6. Changed the handling of character classes; they are now done with a 32-byte
3212     bit map always.
3213    
3214     7. Added the -d and /D options to pcretest to make it possible to look at the
3215     internals of compilation without having to recompile pcre.
3216    
3217    
3218     Version 0.95 23-Sep-97
3219     ----------------------
3220    
3221     1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
3222     \x20 at the start of a run of normal characters. These were being treated as
3223     real characters, instead of the source characters being re-checked.
3224    
3225    
3226     Version 0.94 18-Sep-97
3227     ----------------------
3228    
3229     1. The functions are now thread-safe, with the caveat that the global variables
3230     containing pointers to malloc() and free() or alternative functions are the
3231     same for all threads.
3232    
3233     2. Get pcre_study() to generate a bitmap of initial characters for non-
3234     anchored patterns when this is possible, and use it if passed to pcre_exec().
3235    
3236    
3237     Version 0.93 15-Sep-97
3238     ----------------------
3239    
3240     1. /(b)|(:+)/ was computing an incorrect first character.
3241    
3242     2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
3243     but not actually doing anything yet.
3244    
3245     3. Treat "-" characters in classes that cannot be part of ranges as literals,
3246     as Perl does (e.g. [-az] or [az-]).
3247    
3248     4. Set the anchored flag if a branch starts with .* or .*? because that tests
3249     all possible positions.
3250    
3251     5. Split up into different modules to avoid including unneeded functions in a
3252     compiled binary. However, compile and exec are still in one module. The "study"
3253     function is split off.
3254    
3255     6. The character tables are now in a separate module whose source is generated
3256     by an auxiliary program - but can then be edited by hand if required. There are
3257     now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
3258     toupper() in the code.
3259    
3260     7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
3261     make them global. Abolish the function for setting them, as the caller can now
3262     set them directly.
3263    
3264    
3265     Version 0.92 11-Sep-97
3266     ----------------------
3267    
3268     1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
3269     (e.g. /a{1,3}/) was broken (I mis-optimized it).
3270    
3271     2. Caseless matching was not working in character classes if the characters in
3272     the pattern were in upper case.
3273    
3274     3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
3275    
3276     4. Make PCRE_ANCHORED public and accept as a compile option.
3277    
3278     5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
3279     PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
3280     pass them.
3281    
3282     6. Give an error if bad option bits passed at compile or run time.
3283    
3284     7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
3285     pcretest to cause it to pass that flag.
3286    
3287     8. Add pcre_info(), to get the number of identifying subpatterns, the stored
3288     options, and the first character, if set.
3289    
3290     9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
3291    
3292    
3293     Version 0.91 10-Sep-97
3294     ----------------------
3295    
3296     1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
3297     match the empty string as in /(a*)*/. It was looping and ultimately crashing.
3298    
3299     2. PCRE was looping on encountering an indefinitely repeated back reference to
3300     a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
3301     Perl does - treats the match as successful.
3302    
3303     ****

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