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Revision 205 - (hide annotations) (download)
Fri Aug 3 13:18:33 2007 UTC (7 years, 1 month ago) by ph10
File size: 134202 byte(s)
Fix bugs with [\E] and [\Q\E].

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

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