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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4    Version 6.3 15-Aug-05
5    ---------------------
6    
7     1. The file libpcre.pc.in did not have general read permission in the tarball.
8    
9     2. There were some problems when building without C++ support:
10    
11        (a) If C++ support was not built, "make install" and "make test" still
12            tried to test it.
13    
14        (b) There were problems when the value of CXX was explicitly set. Some
15            changes have been made to try to fix these, and ...
16    
17        (c) --disable-cpp can now be used to explicitly disable C++ support.
18    
19        (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
20            backslash in a target when C++ was disabled. This confuses some
21            versions of "make", apparently. Using an intermediate variable solves
22            this. (Same for CPP_LOBJ.)
23    
24     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
25        (non-Windows) now includes $(CFLAGS) because these flags are sometimes
26        necessary on certain architectures.
27    
28     4. Added a setting of -export-symbols-regex to the link command to remove
29        those symbols that are exported in the C sense, but actually are local
30        within the library, and not documented. Their names all begin with
31        "_pcre_". This is not a perfect job, because (a) we have to except some
32        symbols that pcretest ("illegally") uses, and (b) the facility isn't always
33        available (and never for static libraries). I have made a note to try to
34        find a way round (a) in the future.
35    
36    
37    Version 6.2 01-Aug-05
38    ---------------------
39    
40     1. There was no test for integer overflow of quantifier values. A construction
41        such as {1111111111111111} would give undefined results. What is worse, if
42        a minimum quantifier for a parenthesized subpattern overflowed and became
43        negative, the calculation of the memory size went wrong. This could have
44        led to memory overwriting.
45    
46     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
47    
48     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
49        operating environments where this matters.
50    
51     4. Applied Giuseppe Maxia's patch to add additional features for controlling
52        PCRE options from within the C++ wrapper.
53    
54     5. Named capturing subpatterns were not being correctly counted when a pattern
55        was compiled. This caused two problems: (a) If there were more than 100
56        such subpatterns, the calculation of the memory needed for the whole
57        compiled pattern went wrong, leading to an overflow error. (b) Numerical
58        back references of the form \12, where the number was greater than 9, were
59        not recognized as back references, even though there were sufficient
60        previous subpatterns.
61    
62     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
63        versions of gcc, e.g. 2.95.4.
64    
65    
66    Version 6.1 21-Jun-05
67    ---------------------
68    
69     1. There was one reference to the variable "posix" in pcretest.c that was not
70        surrounded by "#if !defined NOPOSIX".
71    
72     2. Make it possible to compile pcretest without DFA support, UTF8 support, or
73        the cross-check on the old pcre_info() function, for the benefit of the
74        cut-down version of PCRE that is currently imported into Exim.
75    
76     3. A (silly) pattern starting with (?i)(?-i) caused an internal space
77        allocation error. I've done the easy fix, which wastes 2 bytes for sensible
78        patterns that start (?i) but I don't think that matters. The use of (?i) is
79        just an example; this all applies to the other options as well.
80    
81     4. Since libtool seems to echo the compile commands it is issuing, the output
82        from "make" can be reduced a bit by putting "@" in front of each libtool
83        compile command.
84    
85     5. Patch from the folks at Google for configure.in to be a bit more thorough
86        in checking for a suitable C++ installation before trying to compile the
87        C++ stuff. This should fix a reported problem when a compiler was present,
88        but no suitable headers.
89    
90     6. The man pages all had just "PCRE" as their title. I have changed them to
91        be the relevant file name. I have also arranged that these names are
92        retained in the file doc/pcre.txt, which is a concatenation in text format
93        of all the man pages except the little individual ones for each function.
94    
95     7. The NON-UNIX-USE file had not been updated for the different set of source
96        files that come with release 6. I also added a few comments about the C++
97        wrapper.
98    
99    
100    Version 6.0 07-Jun-05
101    ---------------------
102    
103     1. Some minor internal re-organization to help with my DFA experiments.
104    
105     2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
106        didn't matter for the library itself when fully configured, but did matter
107        when compiling without UCP support, or within Exim, where the ucp files are
108        not imported.
109    
110     3. Refactoring of the library code to split up the various functions into
111        different source modules. The addition of the new DFA matching code (see
112        below) to a single monolithic source would have made it really too
113        unwieldy, quite apart from causing all the code to be include in a
114        statically linked application, when only some functions are used. This is
115        relevant even without the DFA addition now that patterns can be compiled in
116        one application and matched in another.
117    
118        The downside of splitting up is that there have to be some external
119        functions and data tables that are used internally in different modules of
120        the library but which are not part of the API. These have all had their
121        names changed to start with "_pcre_" so that they are unlikely to clash
122        with other external names.
123    
124     4. Added an alternate matching function, pcre_dfa_exec(), which matches using
125        a different (DFA) algorithm. Although it is slower than the original
126        function, it does have some advantages for certain types of matching
127        problem.
128    
129     5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
130        including restarting after a partial match.
131    
132     6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
133        defined when compiling for Windows was sent to me. I have put it into the
134        code, though I have no means of testing or verifying it.
135    
136     7. Added the pcre_refcount() auxiliary function.
137    
138     8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
139        match before or at the first newline in the subject string. In pcretest,
140        the /f option on a pattern can be used to set this.
141    
142     9. A repeated \w when used in UTF-8 mode with characters greater than 256
143        would behave wrongly. This has been present in PCRE since release 4.0.
144    
145    10. A number of changes to the pcregrep command:
146    
147        (a) Refactored how -x works; insert ^(...)$ instead of setting
148            PCRE_ANCHORED and checking the length, in preparation for adding
149            something similar for -w.
150    
151        (b) Added the -w (match as a word) option.
152    
153        (c) Refactored the way lines are read and buffered so as to have more
154            than one at a time available.
155    
156        (d) Implemented a pcregrep test script.
157    
158        (e) Added the -M (multiline match) option. This allows patterns to match
159            over several lines of the subject. The buffering ensures that at least
160            8K, or the rest of the document (whichever is the shorter) is available
161            for matching (and similarly the previous 8K for lookbehind assertions).
162    
163        (f) Changed the --help output so that it now says
164    
165              -w, --word-regex(p)
166    
167            instead of two lines, one with "regex" and the other with "regexp"
168            because that confused at least one person since the short forms are the
169            same. (This required a bit of code, as the output is generated
170            automatically from a table. It wasn't just a text change.)
171    
172        (g) -- can be used to terminate pcregrep options if the next thing isn't an
173            option but starts with a hyphen. Could be a pattern or a path name
174            starting with a hyphen, for instance.
175    
176        (h) "-" can be given as a file name to represent stdin.
177    
178        (i) When file names are being printed, "(standard input)" is used for
179            the standard input, for compatibility with GNU grep. Previously
180            "<stdin>" was used.
181    
182        (j) The option --label=xxx can be used to supply a name to be used for
183            stdin when file names are being printed. There is no short form.
184    
185        (k) Re-factored the options decoding logic because we are going to add
186            two more options that take data. Such options can now be given in four
187            different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
188    
189        (l) Added the -A, -B, and -C options for requesting that lines of context
190            around matches be printed.
191    
192        (m) Added the -L option to print the names of files that do not contain
193            any matching lines, that is, the complement of -l.
194    
195        (n) The return code is 2 if any file cannot be opened, but pcregrep does
196            continue to scan other files.
197    
198        (o) The -s option was incorrectly implemented. For compatibility with other
199            greps, it now suppresses the error message for a non-existent or non-
200            accessible file (but not the return code). There is a new option called
201            -q that suppresses the output of matching lines, which was what -s was
202            previously doing.
203    
204        (p) Added --include and --exclude options to specify files for inclusion
205            and exclusion when recursing.
206    
207    11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
208        Hopefully, it now does.
209    
210    12. Missing cast in pcre_study().
211    
212    13. Added an "uninstall" target to the makefile.
213    
214    14. Replaced "extern" in the function prototypes in Makefile.in with
215        "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
216        world, but is set differently for Windows.
217    
218    15. Added a second compiling function called pcre_compile2(). The only
219        difference is that it has an extra argument, which is a pointer to an
220        integer error code. When there is a compile-time failure, this is set
221        non-zero, in addition to the error test pointer being set to point to an
222        error message. The new argument may be NULL if no error number is required
223        (but then you may as well call pcre_compile(), which is now just a
224        wrapper). This facility is provided because some applications need a
225        numeric error indication, but it has also enabled me to tidy up the way
226        compile-time errors are handled in the POSIX wrapper.
227    
228    16. Added VPATH=.libs to the makefile; this should help when building with one
229        prefix path and installing with another. (Or so I'm told by someone who
230        knows more about this stuff than I do.)
231    
232    17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
233        passes PCRE_DOTALL to the pcre_compile() function, making the "." character
234        match everything, including newlines. This is not POSIX-compatible, but
235        somebody wanted the feature. From pcretest it can be activated by using
236        both the P and the s flags.
237    
238    18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
239    
240    19. libpcre.pc was being incorrectly installed as executable.
241    
242    20. A couple of places in pcretest check for end-of-line by looking for '\n';
243        it now also looks for '\r' so that it will work unmodified on Windows.
244    
245    21. Added Google's contributed C++ wrapper to the distribution.
246    
247    22. Added some untidy missing memory free() calls in pcretest, to keep
248        Electric Fence happy when testing.
249    
250    
251    
252    Version 5.0 13-Sep-04
253    ---------------------
254    
255     1. Internal change: literal characters are no longer packed up into items
256        containing multiple characters in a single byte-string. Each character
257        is now matched using a separate opcode. However, there may be more than one
258        byte in the character in UTF-8 mode.
259    
260     2. The pcre_callout_block structure has two new fields: pattern_position and
261        next_item_length. These contain the offset in the pattern to the next match
262        item, and its length, respectively.
263    
264     3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
265        insertion of callouts before each pattern item. Added the /C option to
266        pcretest to make use of this.
267    
268     4. On the advice of a Windows user, the lines
269    
270          #if defined(_WIN32) || defined(WIN32)
271          _setmode( _fileno( stdout ), 0x8000 );
272          #endif  /* defined(_WIN32) || defined(WIN32) */
273    
274        have been added to the source of pcretest. This apparently does useful
275        magic in relation to line terminators.
276    
277     5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
278        for the benefit of those environments where the "b" makes a difference.
279    
280     6. The icc compiler has the same options as gcc, but "configure" doesn't seem
281        to know about it. I have put a hack into configure.in that adds in code
282        to set GCC=yes if CC=icc. This seems to end up at a point in the
283        generated configure script that is early enough to affect the setting of
284        compiler options, which is what is needed, but I have no means of testing
285        whether it really works. (The user who reported this had patched the
286        generated configure script, which of course I cannot do.)
287    
288        LATER: After change 22 below (new libtool files), the configure script
289        seems to know about icc (and also ecc). Therefore, I have commented out
290        this hack in configure.in.
291    
292     7. Added support for pkg-config (2 patches were sent in).
293    
294     8. Negated POSIX character classes that used a combination of internal tables
295        were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
296        [[:^ascii]]. Typically, they would match almost any characters. The other
297        POSIX classes were not broken in this way.
298    
299     9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
300        to find the match, as PCRE was deluded into thinking that the match had to
301        start at the start point or following a newline. The same bug applied to
302        patterns with negative forward assertions or any backward assertions
303        preceding ".*" at the start, unless the pattern required a fixed first
304        character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
305    
306    10. In UTF-8 mode, when moving forwards in the subject after a failed match
307        starting at the last subject character, bytes beyond the end of the subject
308        string were read.
309    
310    11. Renamed the variable "class" as "classbits" to make life easier for C++
311        users. (Previously there was a macro definition, but it apparently wasn't
312        enough.)
313    
314    12. Added the new field "tables" to the extra data so that tables can be passed
315        in at exec time, or the internal tables can be re-selected. This allows
316        a compiled regex to be saved and re-used at a later time by a different
317        program that might have everything at different addresses.
318    
319    13. Modified the pcre-config script so that, when run on Solaris, it shows a
320        -R library as well as a -L library.
321    
322    14. The debugging options of pcretest (-d on the command line or D on a
323        pattern) showed incorrect output for anything following an extended class
324        that contained multibyte characters and which was followed by a quantifier.
325    
326    15. Added optional support for general category Unicode character properties
327        via the \p, \P, and \X escapes. Unicode property support implies UTF-8
328        support. It adds about 90K to the size of the library. The meanings of the
329        inbuilt class escapes such as \d and \s have NOT been changed.
330    
331    16. Updated pcredemo.c to include calls to free() to release the memory for the
332        compiled pattern.
333    
334    17. The generated file chartables.c was being created in the source directory
335        instead of in the building directory. This caused the build to fail if the
336        source directory was different from the building directory, and was
337        read-only.
338    
339    18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
340        file. No doubt somebody will tell me if they don't make sense... Also added
341        Dan Mooney's comments about building on OpenVMS.
342    
343    19. Added support for partial matching via the PCRE_PARTIAL option for
344        pcre_exec() and the \P data escape in pcretest.
345    
346    20. Extended pcretest with 3 new pattern features:
347    
348        (i)   A pattern option of the form ">rest-of-line" causes pcretest to
349              write the compiled pattern to the file whose name is "rest-of-line".
350              This is a straight binary dump of the data, with the saved pointer to
351              the character tables forced to be NULL. The study data, if any, is
352              written too. After writing, pcretest reads a new pattern.
353    
354        (ii)  If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
355              compiled pattern from the given file. There must not be any
356              occurrences of "<" in the file name (pretty unlikely); if there are,
357              pcretest will instead treat the initial "<" as a pattern delimiter.
358              After reading in the pattern, pcretest goes on to read data lines as
359              usual.
360    
361        (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
362              and 16-bit fields in a compiled pattern, to simulate a pattern that
363              was compiled on a host of opposite endianness.
364    
365    21. The pcre-exec() function can now cope with patterns that were compiled on
366        hosts of opposite endianness, with this restriction:
367    
368          As for any compiled expression that is saved and used later, the tables
369          pointer field cannot be preserved; the extra_data field in the arguments
370          to pcre_exec() should be used to pass in a tables address if a value
371          other than the default internal tables were used at compile time.
372    
373    22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
374        now diagnosed as an error. Previously, most of the time, a negative number
375        would have been treated as zero, but if in addition "ovector" was passed as
376        NULL, a crash could occur.
377    
378    23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
379        new versions from the libtool 1.5 distribution (the last one is a copy of
380        a file called libtool.m4). This seems to have fixed the need to patch
381        "configure" to support Darwin 1.3 (which I used to do). However, I still
382        had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
383        workstation).
384    
385    24. Changed the PCRE licence to be the more standard "BSD" licence.
386    
387    
388    Version 4.5 01-Dec-03
389    ---------------------
390    
391     1. There has been some re-arrangement of the code for the match() function so
392        that it can be compiled in a version that does not call itself recursively.
393        Instead, it keeps those local variables that need separate instances for
394        each "recursion" in a frame on the heap, and gets/frees frames whenever it
395        needs to "recurse". Keeping track of where control must go is done by means
396        of setjmp/longjmp. The whole thing is implemented by a set of macros that
397        hide most of the details from the main code, and operates only if
398        NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
399        "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
400        operating.
401    
402        To make it easier for callers to provide specially tailored get/free
403        functions for this usage, two new functions, pcre_stack_malloc, and
404        pcre_stack_free, are used. They are always called in strict stacking order,
405        and the size of block requested is always the same.
406    
407        The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
408        PCRE has been compiled to use the stack or the heap for recursion. The
409        -C option of pcretest uses this to show which version is compiled.
410    
411        A new data escape \S, is added to pcretest; it causes the amounts of store
412        obtained and freed by both kinds of malloc/free at match time to be added
413        to the output.
414    
415     2. Changed the locale test to use "fr_FR" instead of "fr" because that's
416        what's available on my current Linux desktop machine.
417    
418     3. When matching a UTF-8 string, the test for a valid string at the start has
419        been extended. If start_offset is not zero, PCRE now checks that it points
420        to a byte that is the start of a UTF-8 character. If not, it returns
421        PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
422        this is necessary because there may be backward assertions in the pattern.
423        When matching the same subject several times, it may save resources to use
424        PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
425    
426     4. The code for checking the validity of UTF-8 strings has been tightened so
427        that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
428        containing "overlong sequences".
429    
430     5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
431        I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
432        should have been "&", but it just so happened that all the cases this let
433        through by mistake were picked up later in the function.
434    
435     6. I had used a variable called "isblank" - this is a C99 function, causing
436        some compilers to warn. To avoid this, I renamed it (as "blankclass").
437    
438     7. Cosmetic: (a) only output another newline at the end of pcretest if it is
439        prompting; (b) run "./pcretest /dev/null" at the start of the test script
440        so the version is shown; (c) stop "make test" echoing "./RunTest".
441    
442     8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
443    
444     9. The prototype for memmove() for systems that don't have it was using
445        size_t, but the inclusion of the header that defines size_t was later. I've
446        moved the #includes for the C headers earlier to avoid this.
447    
448    10. Added some adjustments to the code to make it easier to compiler on certain
449        special systems:
450    
451          (a) Some "const" qualifiers were missing.
452          (b) Added the macro EXPORT before all exported functions; by default this
453              is defined to be empty.
454          (c) Changed the dftables auxiliary program (that builds chartables.c) so
455              that it reads its output file name as an argument instead of writing
456              to the standard output and assuming this can be redirected.
457    
458    11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
459        class containing characters with values greater than 255, PCRE compilation
460        went into a loop.
461    
462    12. A recursive reference to a subpattern that was within another subpattern
463        that had a minimum quantifier of zero caused PCRE to crash. For example,
464        (x(y(?2))z)? provoked this bug with a subject that got as far as the
465        recursion. If the recursively-called subpattern itself had a zero repeat,
466        that was OK.
467    
468    13. In pcretest, the buffer for reading a data line was set at 30K, but the
469        buffer into which it was copied (for escape processing) was still set at
470        1024, so long lines caused crashes.
471    
472    14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
473        "internal error: code overflow...". This applied to any character class
474        that was followed by a possessive quantifier.
475    
476    15. Modified the Makefile to add libpcre.la as a prerequisite for
477        libpcreposix.la because I was told this is needed for a parallel build to
478        work.
479    
480    16. If a pattern that contained .* following optional items at the start was
481        studied, the wrong optimizing data was generated, leading to matching
482        errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
483        matching string must start with a or b or c. The correct conclusion for
484        this pattern is that a match can start with any character.
485    
486    
487    Version 4.4 13-Aug-03
488    ---------------------
489    
490     1. In UTF-8 mode, a character class containing characters with values between
491        127 and 255 was not handled correctly if the compiled pattern was studied.
492        In fixing this, I have also improved the studying algorithm for such
493        classes (slightly).
494    
495     2. Three internal functions had redundant arguments passed to them. Removal
496        might give a very teeny performance improvement.
497    
498     3. Documentation bug: the value of the capture_top field in a callout is *one
499        more than* the number of the hightest numbered captured substring.
500    
501     4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
502        in incorrectly linking with a previously installed version. They now link
503        explicitly with libpcre.la.
504    
505     5. configure.in no longer needs to recognize Cygwin specially.
506    
507     6. A problem in pcre.in for Windows platforms is fixed.
508    
509     7. If a pattern was successfully studied, and the -d (or /D) flag was given to
510        pcretest, it used to include the size of the study block as part of its
511        output. Unfortunately, the structure contains a field that has a different
512        size on different hardware architectures. This meant that the tests that
513        showed this size failed. As the block is currently always of a fixed size,
514        this information isn't actually particularly useful in pcretest output, so
515        I have just removed it.
516    
517     8. Three pre-processor statements accidentally did not start in column 1.
518        Sadly, there are *still* compilers around that complain, even though
519        standard C has not required this for well over a decade. Sigh.
520    
521     9. In pcretest, the code for checking callouts passed small integers in the
522        callout_data field, which is a void * field. However, some picky compilers
523        complained about the casts involved for this on 64-bit systems. Now
524        pcretest passes the address of the small integer instead, which should get
525        rid of the warnings.
526    
527    10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
528        both compile and run time, and gives an error if an invalid UTF-8 sequence
529        is found. There is a option for disabling this check in cases where the
530        string is known to be correct and/or the maximum performance is wanted.
531    
532    11. In response to a bug report, I changed one line in Makefile.in from
533    
534            -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
535        to
536            -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
537    
538        to look similar to other lines, but I have no way of telling whether this
539        is the right thing to do, as I do not use Windows. No doubt I'll get told
540        if it's wrong...
541    
542    
543    Version 4.3 21-May-03
544    ---------------------
545    
546    1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
547       Makefile.
548    
549    2. Some refactoring to improve the quality of the code:
550    
551       (i)   The utf8_table... variables are now declared "const".
552    
553       (ii)  The code for \cx, which used the "case flipping" table to upper case
554             lower case letters, now just substracts 32. This is ASCII-specific,
555             but the whole concept of \cx is ASCII-specific, so it seems
556             reasonable.
557    
558       (iii) PCRE was using its character types table to recognize decimal and
559             hexadecimal digits in the pattern. This is silly, because it handles
560             only 0-9, a-f, and A-F, but the character types table is locale-
561             specific, which means strange things might happen. A private
562             table is now used for this - though it costs 256 bytes, a table is
563             much faster than multiple explicit tests. Of course, the standard
564             character types table is still used for matching digits in subject
565             strings against \d.
566    
567       (iv)  Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
568             ending in _t are). So I've renamed it as ESC_tee.
569    
570    3. The first argument for regexec() in the POSIX wrapper should have been
571       defined as "const".
572    
573    4. Changed pcretest to use malloc() for its buffers so that they can be
574       Electric Fenced for debugging.
575    
576    5. There were several places in the code where, in UTF-8 mode, PCRE would try
577       to read one or more bytes before the start of the subject string. Often this
578       had no effect on PCRE's behaviour, but in some circumstances it could
579       provoke a segmentation fault.
580    
581    6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
582       to try to read one or more bytes before the start of the subject string.
583    
584    7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
585       UTF-8 support could misbehave in various ways if the subject string
586       contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
587       area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
588       back over UTF-8 characters.)
589    
590    
591    Version 4.2 14-Apr-03
592    ---------------------
593    
594    1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
595    
596    2. Changes to the building process, supplied by Ronald Landheer-Cieslak
597         [ON_WINDOWS]: new variable, "#" on non-Windows platforms
598         [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
599         [WIN_PREFIX]: new variable, "cyg" for Cygwin
600         * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
601           and BUILD_EXEEXT
602         Note: automatic setting of the BUILD variables is not yet working
603         set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
604           compile-time but not at link-time
605         [LINK]: use for linking executables only
606         make different versions for Windows and non-Windows
607         [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
608           libraries
609         [LINK_FOR_BUILD]: new variable
610         [OBJEXT]: use throughout
611         [EXEEXT]: use throughout
612         <winshared>: new target
613         <wininstall>: new target
614         <dftables.o>: use native compiler
615         <dftables>: use native linker
616         <install>: handle Windows platform correctly
617         <clean>: ditto
618         <check>: ditto
619         copy DLL to top builddir before testing
620    
621       As part of these changes, -no-undefined was removed again. This was reported
622       to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
623       in any case.
624    
625    3. Some tidies to get rid of compiler warnings:
626    
627       . In the match_data structure, match_limit was an unsigned long int, whereas
628         match_call_count was an int. I've made them both unsigned long ints.
629    
630       . In pcretest the fact that a const uschar * doesn't automatically cast to
631         a void * provoked a warning.
632    
633       . Turning on some more compiler warnings threw up some "shadow" variables
634         and a few more missing casts.
635    
636    4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
637       option, a class that contained a single character with a value between 128
638       and 255 (e.g. /[\xFF]/) caused PCRE to crash.
639    
640    5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
641       option, a class that contained several characters, but with at least one
642       whose value was between 128 and 255 caused PCRE to crash.
643    
644    
645    Version 4.1 12-Mar-03
646    ---------------------
647    
648    1. Compiling with gcc -pedantic found a couple of places where casts were
649    needed, and a string in dftables.c that was longer than standard compilers are
650    required to support.
651    
652    2. Compiling with Sun's compiler found a few more places where the code could
653    be tidied up in order to avoid warnings.
654    
655    3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
656    first of these names is deprecated in the latest Autoconf in favour of the name
657    CC_FOR_BUILD, because "host" is typically used to mean the system on which the
658    compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
659    analogy I have changed it to CFLAGS_FOR_BUILD.
660    
661    4. Added -no-undefined to the linking command in the Makefile, because this is
662    apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
663    linking step for the pcreposix library.
664    
665    5. PCRE was failing to diagnose the case of two named groups with the same
666    name.
667    
668    6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
669    literal character that is needed in the subject for a match, and scans along to
670    ensure that it is present before embarking on the full matching process. This
671    saves time in cases of nested unlimited repeats that are never going to match.
672    Problem: the scan can take a lot of time if the subject is very long (e.g.
673    megabytes), thus penalizing straightforward matches. It is now done only if the
674    amount of subject to be scanned is less than 1000 bytes.
675    
676    7. A lesser problem with the same optimization is that it was recording the
677    first character of an anchored pattern as "needed", thus provoking a search
678    right along the subject, even when the first match of the pattern was going to
679    fail. The "needed" character is now not set for anchored patterns, unless it
680    follows something in the pattern that is of non-fixed length. Thus, it still
681    fulfils its original purpose of finding quick non-matches in cases of nested
682    unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
683    
684    
685    Version 4.0 17-Feb-03
686    ---------------------
687    
688    1. If a comment in an extended regex that started immediately after a meta-item
689    extended to the end of string, PCRE compiled incorrect data. This could lead to
690    all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
691    
692    2. Moved to autoconf 2.53 and libtool 1.4.2.
693    
694    3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
695    the special perltest8 script is no longer needed - all the tests can be run
696    from a single perltest script.
697    
698    4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
699    by \s. It has now been removed in PCRE. This means it isn't recognized as
700    whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
701    class [:space:] *does* include VT, thereby creating a mess.
702    
703    5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
704    space and tab.
705    
706    6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
707    its new features into the main test script, reducing the number of scripts.
708    
709    7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
710    were backward compatible, and made the (?i) apply to the whole pattern, as if
711    /i were given. Now it behaves more logically, and applies the option setting
712    only to what follows. PCRE has been changed to follow suit. However, if it
713    finds options settings right at the start of the pattern, it extracts them into
714    the global options, as before. Thus, they show up in the info data.
715    
716    8. Added support for the \Q...\E escape sequence. Characters in between are
717    treated as literals. This is slightly different from Perl in that $ and @ are
718    also handled as literals inside the quotes. In Perl, they will cause variable
719    interpolation. Note the following examples:
720    
721        Pattern            PCRE matches      Perl matches
722    
723        \Qabc$xyz\E        abc$xyz           abc followed by the contents of $xyz
724        \Qabc\$xyz\E       abc\$xyz          abc\$xyz
725        \Qabc\E\$\Qxyz\E   abc$xyz           abc$xyz
726    
727    For compatibility with Perl, \Q...\E sequences are recognized inside character
728    classes as well as outside them.
729    
730    9. Re-organized 3 code statements in pcretest to avoid "overflow in
731    floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
732    (size_t) cast to one statement in pcretest and one in pcreposix to avoid
733    signed/unsigned warnings.
734    
735    10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
736    option for pcretest, so I've replaced it by a simple function that does just
737    that job.
738    
739    11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
740    "pcregrep -".
741    
742    12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
743    Java package. This provides some syntactic sugar for simple cases of what my
744    documentation calls "once-only subpatterns". A pattern such as x*+ is the same
745    as (?>x*). In other words, if what is inside (?>...) is just a single repeated
746    item, you can use this simplified notation. Note that only makes sense with
747    greedy quantifiers. Consequently, the use of the possessive quantifier forces
748    greediness, whatever the setting of the PCRE_UNGREEDY option.
749    
750    13. A change of greediness default within a pattern was not taking effect at
751    the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
752    subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
753    was abstracted outside.
754    
755    14. PCRE now supports the \G assertion. It is true when the current matching
756    position is at the start point of the match. This differs from \A when the
757    starting offset is non-zero. Used with the /g option of pcretest (or similar
758    code), it works in the same way as it does for Perl's /g option. If all
759    alternatives of a regex begin with \G, the expression is anchored to the start
760    match position, and the "anchored" flag is set in the compiled expression.
761    
762    15. Some bugs concerning the handling of certain option changes within patterns
763    have been fixed. These applied to options other than (?ims). For example,
764    "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
765    been the other way round. Some of this was related to change 7 above.
766    
767    16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
768    features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
769    and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
770    POSIX classes only within a class (e.g. /[[:alpha:]]/).
771    
772    17. Added support for Perl's \C escape. This matches one byte, even in UTF8
773    mode. Unlike ".", it always matches newline, whatever the setting of
774    PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
775    assertions. Perl allows it, but it doesn't (in general) work because it can't
776    calculate the length of the lookbehind. At least, that's the case for Perl
777    5.8.0 - I've been told they are going to document that it doesn't work in
778    future.
779    
780    18. Added an error diagnosis for escapes that PCRE does not support: these are
781    \L, \l, \N, \P, \p, \U, \u, and \X.
782    
783    19. Although correctly diagnosing a missing ']' in a character class, PCRE was
784    reading past the end of the pattern in cases such as /[abcd/.
785    
786    20. PCRE was getting more memory than necessary for patterns with classes that
787    contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
788    
789    21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
790    compiling PCRE for use with Virtual Pascal.
791    
792    22. Small fix to the Makefile to make it work properly if the build is done
793    outside the source tree.
794    
795    23. Added a new extension: a condition to go with recursion. If a conditional
796    subpattern starts with (?(R) the "true" branch is used if recursion has
797    happened, whereas the "false" branch is used only at the top level.
798    
799    24. When there was a very long string of literal characters (over 255 bytes
800    without UTF support, over 250 bytes with UTF support), the computation of how
801    much memory was required could be incorrect, leading to segfaults or other
802    strange effects.
803    
804    25. PCRE was incorrectly assuming anchoring (either to start of subject or to
805    start of line for a non-DOTALL pattern) when a pattern started with (.*) and
806    there was a subsequent back reference to those brackets. This meant that, for
807    example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
808    possible to check for precisely this case. All we can do is abandon the
809    optimization if .* occurs inside capturing brackets when there are any back
810    references whatsoever. (See below for a better fix that came later.)
811    
812    26. The handling of the optimization for finding the first character of a
813    non-anchored pattern, and for finding a character that is required later in the
814    match were failing in some cases. This didn't break the matching; it just
815    failed to optimize when it could. The way this is done has been re-implemented.
816    
817    27. Fixed typo in error message for invalid (?R item (it said "(?p").
818    
819    28. Added a new feature that provides some of the functionality that Perl
820    provides with (?{...}). The facility is termed a "callout". The way it is done
821    in PCRE is for the caller to provide an optional function, by setting
822    pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
823    global variable. By default it is unset, which disables all calling out. To get
824    the function called, the regex must include (?C) at appropriate points. This
825    is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
826    This provides a means of identifying different callout points. When PCRE
827    reaches such a point in the regex, if pcre_callout has been set, the external
828    function is called. It is provided with data in a structure called
829    pcre_callout_block, which is defined in pcre.h. If the function returns 0,
830    matching continues; if it returns a non-zero value, the match at the current
831    point fails. However, backtracking will occur if possible. [This was changed
832    later and other features added - see item 49 below.]
833    
834    29. pcretest is upgraded to test the callout functionality. It provides a
835    callout function that displays information. By default, it shows the start of
836    the match and the current position in the text. There are some new data escapes
837    to vary what happens:
838    
839        \C+         in addition, show current contents of captured substrings
840        \C-         do not supply a callout function
841        \C!n        return 1 when callout number n is reached
842        \C!n!m      return 1 when callout number n is reached for the mth time
843    
844    30. If pcregrep was called with the -l option and just a single file name, it
845    output "<stdin>" if a match was found, instead of the file name.
846    
847    31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
848    slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
849    pcre_exec(). This saves a malloc/free per call. The default value of
850    POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
851    when configuring.
852    
853    32. The default maximum size of a compiled pattern is 64K. There have been a
854    few cases of people hitting this limit. The code now uses macros to handle the
855    storing of links as offsets within the compiled pattern. It defaults to 2-byte
856    links, but this can be changed to 3 or 4 bytes by --with-link-size when
857    configuring. Tests 2 and 5 work only with 2-byte links because they output
858    debugging information about compiled patterns.
859    
860    33. Internal code re-arrangements:
861    
862    (a) Moved the debugging function for printing out a compiled regex into
863        its own source file (printint.c) and used #include to pull it into
864        pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
865        separate copies.
866    
867    (b) Defined the list of op-code names for debugging as a macro in
868        internal.h so that it is next to the definition of the opcodes.
869    
870    (c) Defined a table of op-code lengths for simpler skipping along compiled
871        code. This is again a macro in internal.h so that it is next to the
872        definition of the opcodes.
873    
874    34. Added support for recursive calls to individual subpatterns, along the
875    lines of Robin Houston's patch (but implemented somewhat differently).
876    
877    35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
878    allow it to read and process whole directories in Win32. This code was
879    contributed by Lionel Fourquaux; it has not been tested by me.
880    
881    36. Added support for named subpatterns. The Python syntax (?P<name>...) is
882    used to name a group. Names consist of alphanumerics and underscores, and must
883    be unique. Back references use the syntax (?P=name) and recursive calls use
884    (?P>name) which is a PCRE extension to the Python extension. Groups still have
885    numbers. The function pcre_fullinfo() can be used after compilation to extract
886    a name/number map. There are three relevant calls:
887    
888      PCRE_INFO_NAMEENTRYSIZE        yields the size of each entry in the map
889      PCRE_INFO_NAMECOUNT            yields the number of entries
890      PCRE_INFO_NAMETABLE            yields a pointer to the map.
891    
892    The map is a vector of fixed-size entries. The size of each entry depends on
893    the length of the longest name used. The first two bytes of each entry are the
894    group number, most significant byte first. There follows the corresponding
895    name, zero terminated. The names are in alphabetical order.
896    
897    37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
898    case instead of 255. Making it the same both with and without UTF-8 support
899    means that the same test output works with both.
900    
901    38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
902    calling malloc() with a zero argument.
903    
904    39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
905    optimization. I've improved things by keeping a bitmap of backreferences with
906    numbers 1-31 so that if .* occurs inside capturing brackets that are not in
907    fact referenced, the optimization can be applied. It is unlikely that a
908    relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
909    the match to follow \n) will appear inside brackets with a number greater than
910    31, but if it does, any back reference > 31 suppresses the optimization.
911    
912    40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
913    of disabling numbered capturing parentheses. Any opening parenthesis that is
914    not followed by ? behaves as if it were followed by ?: but named parentheses
915    can still be used for capturing (and they will acquire numbers in the usual
916    way).
917    
918    41. Redesigned the return codes from the match() function into yes/no/error so
919    that errors can be passed back from deep inside the nested calls. A malloc
920    failure while inside a recursive subpattern call now causes the
921    PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
922    
923    42. It is now possible to set a limit on the number of times the match()
924    function is called in a call to pcre_exec(). This facility makes it possible to
925    limit the amount of recursion and backtracking, though not in a directly
926    obvious way, because the match() function is used in a number of different
927    circumstances. The count starts from zero for each position in the subject
928    string (for non-anchored patterns). The default limit is, for compatibility, a
929    large number, namely 10 000 000. You can change this in two ways:
930    
931    (a) When configuring PCRE before making, you can use --with-match-limit=n
932        to set a default value for the compiled library.
933    
934    (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
935        a different value is set. See 45 below.
936    
937    If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
938    
939    43. Added a new function pcre_config(int, void *) to enable run-time extraction
940    of things that can be changed at compile time. The first argument specifies
941    what is wanted and the second points to where the information is to be placed.
942    The current list of available information is:
943    
944      PCRE_CONFIG_UTF8
945    
946    The output is an integer that is set to one if UTF-8 support is available;
947    otherwise it is set to zero.
948    
949      PCRE_CONFIG_NEWLINE
950    
951    The output is an integer that it set to the value of the code that is used for
952    newline. It is either LF (10) or CR (13).
953    
954      PCRE_CONFIG_LINK_SIZE
955    
956    The output is an integer that contains the number of bytes used for internal
957    linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
958    
959      PCRE_CONFIG_POSIX_MALLOC_THRESHOLD
960    
961    The output is an integer that contains the threshold above which the POSIX
962    interface uses malloc() for output vectors. See item 31 above.
963    
964      PCRE_CONFIG_MATCH_LIMIT
965    
966    The output is an unsigned integer that contains the default limit of the number
967    of match() calls in a pcre_exec() execution. See 42 above.
968    
969    44. pcretest has been upgraded by the addition of the -C option. This causes it
970    to extract all the available output from the new pcre_config() function, and to
971    output it. The program then exits immediately.
972    
973    45. A need has arisen to pass over additional data with calls to pcre_exec() in
974    order to support additional features. One way would have been to define
975    pcre_exec2() (for example) with extra arguments, but this would not have been
976    extensible, and would also have required all calls to the original function to
977    be mapped to the new one. Instead, I have chosen to extend the mechanism that
978    is used for passing in "extra" data from pcre_study().
979    
980    The pcre_extra structure is now exposed and defined in pcre.h. It currently
981    contains the following fields:
982    
983      flags         a bitmap indicating which of the following fields are set
984      study_data    opaque data from pcre_study()
985      match_limit   a way of specifying a limit on match() calls for a specific
986                      call to pcre_exec()
987      callout_data  data for callouts (see 49 below)
988    
989    The flag bits are also defined in pcre.h, and are
990    
991      PCRE_EXTRA_STUDY_DATA
992      PCRE_EXTRA_MATCH_LIMIT
993      PCRE_EXTRA_CALLOUT_DATA
994    
995    The pcre_study() function now returns one of these new pcre_extra blocks, with
996    the actual study data pointed to by the study_data field, and the
997    PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
998    before. That is, this change is entirely upwards-compatible and requires no
999    change to existing code.
1000    
1001    If you want to pass in additional data to pcre_exec(), you can either place it
1002    in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
1003    block.
1004    
1005    46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
1006    data string contains the escape sequence \M, pcretest calls pcre_exec() several
1007    times with different match limits, until it finds the minimum value needed for
1008    pcre_exec() to complete. The value is then output. This can be instructive; for
1009    most simple matches the number is quite small, but for pathological cases it
1010    gets very large very quickly.
1011    
1012    47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
1013    returns the size of the data block pointed to by the study_data field in a
1014    pcre_extra block, that is, the value that was passed as the argument to
1015    pcre_malloc() when PCRE was getting memory in which to place the information
1016    created by pcre_study(). The fourth argument should point to a size_t variable.
1017    pcretest has been extended so that this information is shown after a successful
1018    pcre_study() call when information about the compiled regex is being displayed.
1019    
1020    48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
1021    because what follows is always an absolute path. (Later: it turns out that this
1022    is more than cosmetic for MinGW, because it doesn't like empty path
1023    components.)
1024    
1025    49. Some changes have been made to the callout feature (see 28 above):
1026    
1027    (i)  A callout function now has three choices for what it returns:
1028    
1029           0  =>  success, carry on matching
1030         > 0  =>  failure at this point, but backtrack if possible
1031         < 0  =>  serious error, return this value from pcre_exec()
1032    
1033         Negative values should normally be chosen from the set of PCRE_ERROR_xxx
1034         values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
1035         "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
1036         use by callout functions. It will never be used by PCRE itself.
1037    
1038    (ii) The pcre_extra structure (see 45 above) has a void * field called
1039         callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
1040         pcre_callout_block structure has a field of the same name. The contents of
1041         the field passed in the pcre_extra structure are passed to the callout
1042         function in the corresponding field in the callout block. This makes it
1043         easier to use the same callout-containing regex from multiple threads. For
1044         testing, the pcretest program has a new data escape
1045    
1046           \C*n        pass the number n (may be negative) as callout_data
1047    
1048         If the callout function in pcretest receives a non-zero value as
1049         callout_data, it returns that value.
1050    
1051    50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
1052    there were some redundant $(CFLAGS) in commands that are now specified as
1053    $(LINK), which already includes $(CFLAGS).
1054    
1055    51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
1056    has been compiled with UTF-8 support *and* pcre_compile() has been compiled
1057    with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
1058    one-byte characters throughout. Note that case-insensitive matching applies
1059    only to characters whose values are less than 256. PCRE doesn't support the
1060    notion of cases for higher-valued characters.
1061    
1062    (i)   A character class whose characters are all within 0-255 is handled as
1063          a bit map, and the map is inverted for negative classes. Previously, a
1064          character > 255 always failed to match such a class; however it should
1065          match if the class was a negative one (e.g. [^ab]). This has been fixed.
1066    
1067    (ii)  A negated character class with a single character < 255 is coded as
1068          "not this character" (OP_NOT). This wasn't working properly when the test
1069          character was multibyte, either singly or repeated.
1070    
1071    (iii) Repeats of multibyte characters are now handled correctly in UTF-8
1072          mode, for example: \x{100}{2,3}.
1073    
1074    (iv)  The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
1075          singly or repeated) now correctly test multibyte characters. However,
1076          PCRE doesn't recognize any characters with values greater than 255 as
1077          digits, spaces, or word characters. Such characters always match \D, \S,
1078          and \W, and never match \d, \s, or \w.
1079    
1080    (v)   Classes may now contain characters and character ranges with values
1081          greater than 255. For example: [ab\x{100}-\x{400}].
1082    
1083    (vi)  pcregrep now has a --utf-8 option (synonym -u) which makes it call
1084          PCRE in UTF-8 mode.
1085    
1086    52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
1087    PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
1088    retained for backwards compatibility. (Note that LASTLITERAL is also a byte
1089    value.)
1090    
1091    53. The single man page has become too large. I have therefore split it up into
1092    a number of separate man pages. These also give rise to individual HTML pages;
1093    these are now put in a separate directory, and there is an index.html page that
1094    lists them all. Some hyperlinking between the pages has been installed.
1095    
1096    54. Added convenience functions for handling named capturing parentheses.
1097    
1098    55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
1099    aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
1100    true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
1101    are faulted.
1102    
1103    56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
1104    calling configure. These values are used when compiling the dftables.c program
1105    which is run to generate the source of the default character tables. They
1106    default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
1107    you will need to set these values.
1108    
1109    57. Updated the building process for Windows DLL, as provided by Fred Cox.
1110    
1111    
1112    Version 3.9 02-Jan-02
1113    ---------------------
1114    
1115    1. A bit of extraneous text had somehow crept into the pcregrep documentation.
1116    
1117    2. If --disable-static was given, the building process failed when trying to
1118    build pcretest and pcregrep. (For some reason it was using libtool to compile
1119    them, which is not right, as they aren't part of the library.)
1120    
1121    
1122    Version 3.8 18-Dec-01
1123    ---------------------
1124    
1125    1. The experimental UTF-8 code was completely screwed up. It was packing the
1126    bytes in the wrong order. How dumb can you get?
1127    
1128    
1129    Version 3.7 29-Oct-01
1130    ---------------------
1131    
1132    1. In updating pcretest to check change 1 of version 3.6, I screwed up.
1133    This caused pcretest, when used on the test data, to segfault. Unfortunately,
1134    this didn't happen under Solaris 8, where I normally test things.
1135    
1136    2. The Makefile had to be changed to make it work on BSD systems, where 'make'
1137    doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
1138    isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
1139    this fix an hour or so after the initial 3.7 release.)
1140    
1141    
1142    Version 3.6 23-Oct-01
1143    ---------------------
1144    
1145    1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
1146    offsets passed as NULL with zero offset count.
1147    
1148    2. The config.guess and config.sub files had not been updated when I moved to
1149    the latest autoconf.
1150    
1151    
1152    Version 3.5 15-Aug-01
1153    ---------------------
1154    
1155    1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
1156    had been forgotten.
1157    
1158    2. By using declared but undefined structures, we can avoid using "void"
1159    definitions in pcre.h while keeping the internal definitions of the structures
1160    private.
1161    
1162    3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
1163    user point of view, this means that both static and shared libraries are built
1164    by default, but this can be individually controlled. More of the work of
1165    handling this static/shared cases is now inside libtool instead of PCRE's make
1166    file.
1167    
1168    4. The pcretest utility is now installed along with pcregrep because it is
1169    useful for users (to test regexs) and by doing this, it automatically gets
1170    relinked by libtool. The documentation has been turned into a man page, so
1171    there are now .1, .txt, and .html versions in /doc.
1172    
1173    5. Upgrades to pcregrep:
1174       (i)   Added long-form option names like gnu grep.
1175       (ii)  Added --help to list all options with an explanatory phrase.
1176       (iii) Added -r, --recursive to recurse into sub-directories.
1177       (iv)  Added -f, --file to read patterns from a file.
1178    
1179    6. pcre_exec() was referring to its "code" argument before testing that
1180    argument for NULL (and giving an error if it was NULL).
1181    
1182    7. Upgraded Makefile.in to allow for compiling in a different directory from
1183    the source directory.
1184    
1185    8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
1186    options bits, the pointer it was passed was to an int instead of to an unsigned
1187    long int. This mattered only on 64-bit systems.
1188    
1189    9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
1190    generated) instead of pcre.in, which it its source. Also made the same change
1191    in several of the .c files.
1192    
1193    10. A new release of gcc defines printf() as a macro, which broke pcretest
1194    because it had an ifdef in the middle of a string argument for printf(). Fixed
1195    by using separate calls to printf().
1196    
1197    11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
1198    script, to force use of CR or LF instead of \n in the source. On non-Unix
1199    systems, the value can be set in config.h.
1200    
1201    12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
1202    absolute limit. Changed the text of the error message to make this clear, and
1203    likewise updated the man page.
1204    
1205    13. The limit of 99 on the number of capturing subpatterns has been removed.
1206    The new limit is 65535, which I hope will not be a "real" limit.
1207    
1208    
1209    Version 3.4 22-Aug-00
1210    ---------------------
1211    
1212    1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
1213    
1214    2. Diagnose condition (?(0) as an error instead of crashing on matching.
1215    
1216    
1217    Version 3.3 01-Aug-00
1218    ---------------------
1219    
1220    1. If an octal character was given, but the value was greater than \377, it
1221    was not getting masked to the least significant bits, as documented. This could
1222    lead to crashes in some systems.
1223    
1224    2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
1225    the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
1226    
1227    3. Added the functions pcre_free_substring() and pcre_free_substring_list().
1228    These just pass their arguments on to (pcre_free)(), but they are provided
1229    because some uses of PCRE bind it to non-C systems that can call its functions,
1230    but cannot call free() or pcre_free() directly.
1231    
1232    4. Add "make test" as a synonym for "make check". Corrected some comments in
1233    the Makefile.
1234    
1235    5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
1236    Makefile.
1237    
1238    6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
1239    command called pgrep for grepping around the active processes.
1240    
1241    7. Added the beginnings of support for UTF-8 character strings.
1242    
1243    8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
1244    RANLIB to ./ltconfig so that they are used by libtool. I think these are all
1245    the relevant ones. (AR is not passed because ./ltconfig does its own figuring
1246    out for the ar command.)
1247    
1248    
1249    Version 3.2 12-May-00
1250    ---------------------
1251    
1252    This is purely a bug fixing release.
1253    
1254    1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
1255    of ZA. This was just one example of several cases that could provoke this bug,
1256    which was introduced by change 9 of version 2.00. The code for breaking
1257    infinite loops after an iteration that matches an empty string was't working
1258    correctly.
1259    
1260    2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
1261    when matched against abbab (for example). After matching an empty string, it
1262    wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
1263    caused it to match further down the string than it should.
1264    
1265    3. The code contained an inclusion of sys/types.h. It isn't clear why this
1266    was there because it doesn't seem to be needed, and it causes trouble on some
1267    systems, as it is not a Standard C header. It has been removed.
1268    
1269    4. Made 4 silly changes to the source to avoid stupid compiler warnings that
1270    were reported on the Macintosh. The changes were from
1271    
1272      while ((c = *(++ptr)) != 0 && c != '\n');
1273    to
1274      while ((c = *(++ptr)) != 0 && c != '\n') ;
1275    
1276    Totally extraordinary, but if that's what it takes...
1277    
1278    5. PCRE is being used in one environment where neither memmove() nor bcopy() is
1279    available. Added HAVE_BCOPY and an autoconf test for it; if neither
1280    HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
1281    assumes the way PCRE uses memmove() (always moving upwards).
1282    
1283    6. PCRE is being used in one environment where strchr() is not available. There
1284    was only one use in pcre.c, and writing it out to avoid strchr() probably gives
1285    faster code anyway.
1286    
1287    
1288    Version 3.1 09-Feb-00
1289    ---------------------
1290    
1291    The only change in this release is the fixing of some bugs in Makefile.in for
1292    the "install" target:
1293    
1294    (1) It was failing to install pcreposix.h.
1295    
1296    (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
1297    
1298    
1299    Version 3.0 01-Feb-00
1300    ---------------------
1301    
1302    1. Add support for the /+ modifier to perltest (to output $` like it does in
1303    pcretest).
1304    
1305    2. Add support for the /g modifier to perltest.
1306    
1307    3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
1308    matches null strings.
1309    
1310    4. Fix perltest so that it doesn't do unwanted things when fed an empty
1311    pattern. Perl treats empty patterns specially - it reuses the most recent
1312    pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
1313    effect.
1314    
1315    5. The POSIX interface was broken in that it was just handing over the POSIX
1316    captured string vector to pcre_exec(), but (since release 2.00) PCRE has
1317    required a bigger vector, with some working space on the end. This means that
1318    the POSIX wrapper now has to get and free some memory, and copy the results.
1319    
1320    6. Added some simple autoconf support, placing the test data and the
1321    documentation in separate directories, re-organizing some of the
1322    information files, and making it build pcre-config (a GNU standard). Also added
1323    libtool support for building PCRE as a shared library, which is now the
1324    default.
1325    
1326    7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
1327    09 are not valid octal constants. Single digits will be used for minor values
1328    less than 10.
1329    
1330    8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
1331    existing programs that set these in the POSIX interface can use PCRE without
1332    modification.
1333    
1334    9. Added a new function, pcre_fullinfo() with an extensible interface. It can
1335    return all that pcre_info() returns, plus additional data. The pcre_info()
1336    function is retained for compatibility, but is considered to be obsolete.
1337    
1338    10. Added experimental recursion feature (?R) to handle one common case that
1339    Perl 5.6 will be able to do with (?p{...}).
1340    
1341    11. Added support for POSIX character classes like [:alpha:], which Perl is
1342    adopting.
1343    
1344    
1345    Version 2.08 31-Aug-99
1346    ----------------------
1347    
1348    1. When startoffset was not zero and the pattern began with ".*", PCRE was not
1349    trying to match at the startoffset position, but instead was moving forward to
1350    the next newline as if a previous match had failed.
1351    
1352    2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
1353    and could get into a loop if a null string was matched other than at the start
1354    of the subject.
1355    
1356    3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
1357    be distinguished at compile time, and for completeness also added PCRE_DATE.
1358    
1359    5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
1360    in GnuWin32 environments.
1361    
1362    
1363    Version 2.07 29-Jul-99
1364    ----------------------
1365    
1366    1. The documentation is now supplied in plain text form and HTML as well as in
1367    the form of man page sources.
1368    
1369    2. C++ compilers don't like assigning (void *) values to other pointer types.
1370    In particular this affects malloc(). Although there is no problem in Standard
1371    C, I've put in casts to keep C++ compilers happy.
1372    
1373    3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
1374    should be (const char *).
1375    
1376    4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
1377    be useful for non-Unix systems who don't want to bother with the POSIX stuff.
1378    However, I haven't made this a standard facility. The documentation doesn't
1379    mention it, and the Makefile doesn't support it.
1380    
1381    5. The Makefile now contains an "install" target, with editable destinations at
1382    the top of the file. The pcretest program is not installed.
1383    
1384    6. pgrep -V now gives the PCRE version number and date.
1385    
1386    7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
1387    causing the entire string to be ignored, instead of just the last character.
1388    
1389    8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
1390    non-matching string, it can take a very, very long time, even for strings of
1391    quite modest length, because of the nested recursion. PCRE now does better in
1392    some of these cases. It does this by remembering the last required literal
1393    character in the pattern, and pre-searching the subject to ensure it is present
1394    before running the real match. In other words, it applies a heuristic to detect
1395    some types of certain failure quickly, and in the above example, if presented
1396    with a string that has no trailing " it gives "no match" very quickly.
1397    
1398    9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
1399    other alternatives are tried instead.
1400    
1401    
1402    Version 2.06 09-Jun-99
1403    ----------------------
1404    
1405    1. Change pcretest's output for amount of store used to show just the code
1406    space, because the remainder (the data block) varies in size between 32-bit and
1407    64-bit systems.
1408    
1409    2. Added an extra argument to pcre_exec() to supply an offset in the subject to
1410    start matching at. This allows lookbehinds to work when searching for multiple
1411    occurrences in a string.
1412    
1413    3. Added additional options to pcretest for testing multiple occurrences:
1414    
1415       /+   outputs the rest of the string that follows a match
1416       /g   loops for multiple occurrences, using the new startoffset argument
1417       /G   loops for multiple occurrences by passing an incremented pointer
1418    
1419    4. PCRE wasn't doing the "first character" optimization for patterns starting
1420    with \b or \B, though it was doing it for other lookbehind assertions. That is,
1421    it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
1422    the letter 'x'. On long subject strings, this gives a significant speed-up.
1423    
1424    
1425    Version 2.05 21-Apr-99
1426    ----------------------
1427    
1428    1. Changed the type of magic_number from int to long int so that it works
1429    properly on 16-bit systems.
1430    
1431    2. Fixed a bug which caused patterns starting with .* not to work correctly
1432    when the subject string contained newline characters. PCRE was assuming
1433    anchoring for such patterns in all cases, which is not correct because .* will
1434    not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
1435    DOTALL is set at top level; otherwise it knows that patterns starting with .*
1436    must be retried after every newline in the subject.
1437    
1438    
1439    Version 2.04 18-Feb-99
1440    ----------------------
1441    
1442    1. For parenthesized subpatterns with repeats whose minimum was zero, the
1443    computation of the store needed to hold the pattern was incorrect (too large).
1444    If such patterns were nested a few deep, this could multiply and become a real
1445    problem.
1446    
1447    2. Added /M option to pcretest to show the memory requirement of a specific
1448    pattern. Made -m a synonym of -s (which does this globally) for compatibility.
1449    
1450    3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
1451    compiled in such a way that the backtracking after subsequent failure was
1452    pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
1453    ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
1454    
1455    
1456    Version 2.03 02-Feb-99
1457    ----------------------
1458    
1459    1. Fixed typo and small mistake in man page.
1460    
1461    2. Added 4th condition (GPL supersedes if conflict) and created separate
1462    LICENCE file containing the conditions.
1463    
1464    3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
1465    Perl, that is the internal \ allows the delimiter to be included in the
1466    pattern. Locked out the use of \ as a delimiter. If \ immediately follows
1467    the final delimiter, add \ to the end of the pattern (to test the error).
1468    
1469    4. Added the convenience functions for extracting substrings after a successful
1470    match. Updated pcretest to make it able to test these functions.
1471    
1472    
1473  Version 2.02 14-Jan-99  Version 2.02 14-Jan-99
1474  ----------------------  ----------------------

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