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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4    Version 6.0 07-Jun-05
5    ---------------------
6    
7     1. Some minor internal re-organization to help with my DFA experiments.
8    
9     2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
10        didn't matter for the library itself when fully configured, but did matter
11        when compiling without UCP support, or within Exim, where the ucp files are
12        not imported.
13    
14     3. Refactoring of the library code to split up the various functions into
15        different source modules. The addition of the new DFA matching code (see
16        below) to a single monolithic source would have made it really too
17        unwieldy, quite apart from causing all the code to be include in a
18        statically linked application, when only some functions are used. This is
19        relevant even without the DFA addition now that patterns can be compiled in
20        one application and matched in another.
21    
22        The downside of splitting up is that there have to be some external
23        functions and data tables that are used internally in different modules of
24        the library but which are not part of the API. These have all had their
25        names changed to start with "_pcre_" so that they are unlikely to clash
26        with other external names.
27    
28     4. Added an alternate matching function, pcre_dfa_exec(), which matches using
29        a different (DFA) algorithm. Although it is slower than the original
30        function, it does have some advantages for certain types of matching
31        problem.
32    
33     5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
34        including restarting after a partial match.
35    
36     6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
37        defined when compiling for Windows was sent to me. I have put it into the
38        code, though I have no means of testing or verifying it.
39    
40     7. Added the pcre_refcount() auxiliary function.
41    
42     8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
43        match before or at the first newline in the subject string. In pcretest,
44        the /f option on a pattern can be used to set this.
45    
46     9. A repeated \w when used in UTF-8 mode with characters greater than 256
47        would behave wrongly. This has been present in PCRE since release 4.0.
48    
49    10. A number of changes to the pcregrep command:
50    
51        (a) Refactored how -x works; insert ^(...)$ instead of setting
52            PCRE_ANCHORED and checking the length, in preparation for adding
53            something similar for -w.
54    
55        (b) Added the -w (match as a word) option.
56    
57        (c) Refactored the way lines are read and buffered so as to have more
58            than one at a time available.
59    
60        (d) Implemented a pcregrep test script.
61    
62        (e) Added the -M (multiline match) option. This allows patterns to match
63            over several lines of the subject. The buffering ensures that at least
64            8K, or the rest of the document (whichever is the shorter) is available
65            for matching (and similarly the previous 8K for lookbehind assertions).
66    
67        (f) Changed the --help output so that it now says
68    
69              -w, --word-regex(p)
70    
71            instead of two lines, one with "regex" and the other with "regexp"
72            because that confused at least one person since the short forms are the
73            same. (This required a bit of code, as the output is generated
74            automatically from a table. It wasn't just a text change.)
75    
76        (g) -- can be used to terminate pcregrep options if the next thing isn't an
77            option but starts with a hyphen. Could be a pattern or a path name
78            starting with a hyphen, for instance.
79    
80        (h) "-" can be given as a file name to represent stdin.
81    
82        (i) When file names are being printed, "(standard input)" is used for
83            the standard input, for compatibility with GNU grep. Previously
84            "<stdin>" was used.
85    
86        (j) The option --label=xxx can be used to supply a name to be used for
87            stdin when file names are being printed. There is no short form.
88    
89        (k) Re-factored the options decoding logic because we are going to add
90            two more options that take data. Such options can now be given in four
91            different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
92    
93        (l) Added the -A, -B, and -C options for requesting that lines of context
94            around matches be printed.
95    
96        (m) Added the -L option to print the names of files that do not contain
97            any matching lines, that is, the complement of -l.
98    
99        (n) The return code is 2 if any file cannot be opened, but pcregrep does
100            continue to scan other files.
101    
102        (o) The -s option was incorrectly implemented. For compatibility with other
103            greps, it now suppresses the error message for a non-existent or non-
104            accessible file (but not the return code). There is a new option called
105            -q that suppresses the output of matching lines, which was what -s was
106            previously doing.
107    
108        (p) Added --include and --exclude options to specify files for inclusion
109            and exclusion when recursing.
110    
111    11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
112        Hopefully, it now does.
113    
114    12. Missing cast in pcre_study().
115    
116    13. Added an "uninstall" target to the makefile.
117    
118    14. Replaced "extern" in the function prototypes in Makefile.in with
119        "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
120        world, but is set differently for Windows.
121    
122    15. Added a second compiling function called pcre_compile2(). The only
123        difference is that it has an extra argument, which is a pointer to an
124        integer error code. When there is a compile-time failure, this is set
125        non-zero, in addition to the error test pointer being set to point to an
126        error message. The new argument may be NULL if no error number is required
127        (but then you may as well call pcre_compile(), which is now just a
128        wrapper). This facility is provided because some applications need a
129        numeric error indication, but it has also enabled me to tidy up the way
130        compile-time errors are handled in the POSIX wrapper.
131    
132    16. Added VPATH=.libs to the makefile; this should help when building with one
133        prefix path and installing with another. (Or so I'm told by someone who
134        knows more about this stuff than I do.)
135    
136    17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
137        passes PCRE_DOTALL to the pcre_compile() function, making the "." character
138        match everything, including newlines. This is not POSIX-compatible, but
139        somebody wanted the feature. From pcretest it can be activated by using
140        both the P and the s flags.
141    
142    18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
143    
144    19. libpcre.pc was being incorrectly installed as executable.
145    
146    20. A couple of places in pcretest check for end-of-line by looking for '\n';
147        it now also looks for '\r' so that it will work unmodified on Windows.
148    
149    21. Added Google's contributed C++ wrapper to the distribution.
150    
151    22. Added some untidy missing memory free() calls in pcretest, to keep
152        Electric Fence happy when testing.
153    
154    
155    
156    Version 5.0 13-Sep-04
157    ---------------------
158    
159     1. Internal change: literal characters are no longer packed up into items
160        containing multiple characters in a single byte-string. Each character
161        is now matched using a separate opcode. However, there may be more than one
162        byte in the character in UTF-8 mode.
163    
164     2. The pcre_callout_block structure has two new fields: pattern_position and
165        next_item_length. These contain the offset in the pattern to the next match
166        item, and its length, respectively.
167    
168     3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
169        insertion of callouts before each pattern item. Added the /C option to
170        pcretest to make use of this.
171    
172     4. On the advice of a Windows user, the lines
173    
174          #if defined(_WIN32) || defined(WIN32)
175          _setmode( _fileno( stdout ), 0x8000 );
176          #endif  /* defined(_WIN32) || defined(WIN32) */
177    
178        have been added to the source of pcretest. This apparently does useful
179        magic in relation to line terminators.
180    
181     5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
182        for the benefit of those environments where the "b" makes a difference.
183    
184     6. The icc compiler has the same options as gcc, but "configure" doesn't seem
185        to know about it. I have put a hack into configure.in that adds in code
186        to set GCC=yes if CC=icc. This seems to end up at a point in the
187        generated configure script that is early enough to affect the setting of
188        compiler options, which is what is needed, but I have no means of testing
189        whether it really works. (The user who reported this had patched the
190        generated configure script, which of course I cannot do.)
191    
192        LATER: After change 22 below (new libtool files), the configure script
193        seems to know about icc (and also ecc). Therefore, I have commented out
194        this hack in configure.in.
195    
196     7. Added support for pkg-config (2 patches were sent in).
197    
198     8. Negated POSIX character classes that used a combination of internal tables
199        were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
200        [[:^ascii]]. Typically, they would match almost any characters. The other
201        POSIX classes were not broken in this way.
202    
203     9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
204        to find the match, as PCRE was deluded into thinking that the match had to
205        start at the start point or following a newline. The same bug applied to
206        patterns with negative forward assertions or any backward assertions
207        preceding ".*" at the start, unless the pattern required a fixed first
208        character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
209    
210    10. In UTF-8 mode, when moving forwards in the subject after a failed match
211        starting at the last subject character, bytes beyond the end of the subject
212        string were read.
213    
214    11. Renamed the variable "class" as "classbits" to make life easier for C++
215        users. (Previously there was a macro definition, but it apparently wasn't
216        enough.)
217    
218    12. Added the new field "tables" to the extra data so that tables can be passed
219        in at exec time, or the internal tables can be re-selected. This allows
220        a compiled regex to be saved and re-used at a later time by a different
221        program that might have everything at different addresses.
222    
223    13. Modified the pcre-config script so that, when run on Solaris, it shows a
224        -R library as well as a -L library.
225    
226    14. The debugging options of pcretest (-d on the command line or D on a
227        pattern) showed incorrect output for anything following an extended class
228        that contained multibyte characters and which was followed by a quantifier.
229    
230    15. Added optional support for general category Unicode character properties
231        via the \p, \P, and \X escapes. Unicode property support implies UTF-8
232        support. It adds about 90K to the size of the library. The meanings of the
233        inbuilt class escapes such as \d and \s have NOT been changed.
234    
235    16. Updated pcredemo.c to include calls to free() to release the memory for the
236        compiled pattern.
237    
238    17. The generated file chartables.c was being created in the source directory
239        instead of in the building directory. This caused the build to fail if the
240        source directory was different from the building directory, and was
241        read-only.
242    
243    18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
244        file. No doubt somebody will tell me if they don't make sense... Also added
245        Dan Mooney's comments about building on OpenVMS.
246    
247    19. Added support for partial matching via the PCRE_PARTIAL option for
248        pcre_exec() and the \P data escape in pcretest.
249    
250    20. Extended pcretest with 3 new pattern features:
251    
252        (i)   A pattern option of the form ">rest-of-line" causes pcretest to
253              write the compiled pattern to the file whose name is "rest-of-line".
254              This is a straight binary dump of the data, with the saved pointer to
255              the character tables forced to be NULL. The study data, if any, is
256              written too. After writing, pcretest reads a new pattern.
257    
258        (ii)  If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
259              compiled pattern from the given file. There must not be any
260              occurrences of "<" in the file name (pretty unlikely); if there are,
261              pcretest will instead treat the initial "<" as a pattern delimiter.
262              After reading in the pattern, pcretest goes on to read data lines as
263              usual.
264    
265        (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
266              and 16-bit fields in a compiled pattern, to simulate a pattern that
267              was compiled on a host of opposite endianness.
268    
269    21. The pcre-exec() function can now cope with patterns that were compiled on
270        hosts of opposite endianness, with this restriction:
271    
272          As for any compiled expression that is saved and used later, the tables
273          pointer field cannot be preserved; the extra_data field in the arguments
274          to pcre_exec() should be used to pass in a tables address if a value
275          other than the default internal tables were used at compile time.
276    
277    22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
278        now diagnosed as an error. Previously, most of the time, a negative number
279        would have been treated as zero, but if in addition "ovector" was passed as
280        NULL, a crash could occur.
281    
282    23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
283        new versions from the libtool 1.5 distribution (the last one is a copy of
284        a file called libtool.m4). This seems to have fixed the need to patch
285        "configure" to support Darwin 1.3 (which I used to do). However, I still
286        had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
287        workstation).
288    
289    24. Changed the PCRE licence to be the more standard "BSD" licence.
290    
291    
292    Version 4.5 01-Dec-03
293    ---------------------
294    
295     1. There has been some re-arrangement of the code for the match() function so
296        that it can be compiled in a version that does not call itself recursively.
297        Instead, it keeps those local variables that need separate instances for
298        each "recursion" in a frame on the heap, and gets/frees frames whenever it
299        needs to "recurse". Keeping track of where control must go is done by means
300        of setjmp/longjmp. The whole thing is implemented by a set of macros that
301        hide most of the details from the main code, and operates only if
302        NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
303        "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
304        operating.
305    
306        To make it easier for callers to provide specially tailored get/free
307        functions for this usage, two new functions, pcre_stack_malloc, and
308        pcre_stack_free, are used. They are always called in strict stacking order,
309        and the size of block requested is always the same.
310    
311        The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
312        PCRE has been compiled to use the stack or the heap for recursion. The
313        -C option of pcretest uses this to show which version is compiled.
314    
315        A new data escape \S, is added to pcretest; it causes the amounts of store
316        obtained and freed by both kinds of malloc/free at match time to be added
317        to the output.
318    
319     2. Changed the locale test to use "fr_FR" instead of "fr" because that's
320        what's available on my current Linux desktop machine.
321    
322     3. When matching a UTF-8 string, the test for a valid string at the start has
323        been extended. If start_offset is not zero, PCRE now checks that it points
324        to a byte that is the start of a UTF-8 character. If not, it returns
325        PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
326        this is necessary because there may be backward assertions in the pattern.
327        When matching the same subject several times, it may save resources to use
328        PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
329    
330     4. The code for checking the validity of UTF-8 strings has been tightened so
331        that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
332        containing "overlong sequences".
333    
334     5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
335        I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
336        should have been "&", but it just so happened that all the cases this let
337        through by mistake were picked up later in the function.
338    
339     6. I had used a variable called "isblank" - this is a C99 function, causing
340        some compilers to warn. To avoid this, I renamed it (as "blankclass").
341    
342     7. Cosmetic: (a) only output another newline at the end of pcretest if it is
343        prompting; (b) run "./pcretest /dev/null" at the start of the test script
344        so the version is shown; (c) stop "make test" echoing "./RunTest".
345    
346     8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
347    
348     9. The prototype for memmove() for systems that don't have it was using
349        size_t, but the inclusion of the header that defines size_t was later. I've
350        moved the #includes for the C headers earlier to avoid this.
351    
352    10. Added some adjustments to the code to make it easier to compiler on certain
353        special systems:
354    
355          (a) Some "const" qualifiers were missing.
356          (b) Added the macro EXPORT before all exported functions; by default this
357              is defined to be empty.
358          (c) Changed the dftables auxiliary program (that builds chartables.c) so
359              that it reads its output file name as an argument instead of writing
360              to the standard output and assuming this can be redirected.
361    
362    11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
363        class containing characters with values greater than 255, PCRE compilation
364        went into a loop.
365    
366    12. A recursive reference to a subpattern that was within another subpattern
367        that had a minimum quantifier of zero caused PCRE to crash. For example,
368        (x(y(?2))z)? provoked this bug with a subject that got as far as the
369        recursion. If the recursively-called subpattern itself had a zero repeat,
370        that was OK.
371    
372    13. In pcretest, the buffer for reading a data line was set at 30K, but the
373        buffer into which it was copied (for escape processing) was still set at
374        1024, so long lines caused crashes.
375    
376    14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
377        "internal error: code overflow...". This applied to any character class
378        that was followed by a possessive quantifier.
379    
380    15. Modified the Makefile to add libpcre.la as a prerequisite for
381        libpcreposix.la because I was told this is needed for a parallel build to
382        work.
383    
384    16. If a pattern that contained .* following optional items at the start was
385        studied, the wrong optimizing data was generated, leading to matching
386        errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
387        matching string must start with a or b or c. The correct conclusion for
388        this pattern is that a match can start with any character.
389    
390    
391    Version 4.4 13-Aug-03
392    ---------------------
393    
394     1. In UTF-8 mode, a character class containing characters with values between
395        127 and 255 was not handled correctly if the compiled pattern was studied.
396        In fixing this, I have also improved the studying algorithm for such
397        classes (slightly).
398    
399     2. Three internal functions had redundant arguments passed to them. Removal
400        might give a very teeny performance improvement.
401    
402     3. Documentation bug: the value of the capture_top field in a callout is *one
403        more than* the number of the hightest numbered captured substring.
404    
405     4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
406        in incorrectly linking with a previously installed version. They now link
407        explicitly with libpcre.la.
408    
409     5. configure.in no longer needs to recognize Cygwin specially.
410    
411     6. A problem in pcre.in for Windows platforms is fixed.
412    
413     7. If a pattern was successfully studied, and the -d (or /D) flag was given to
414        pcretest, it used to include the size of the study block as part of its
415        output. Unfortunately, the structure contains a field that has a different
416        size on different hardware architectures. This meant that the tests that
417        showed this size failed. As the block is currently always of a fixed size,
418        this information isn't actually particularly useful in pcretest output, so
419        I have just removed it.
420    
421     8. Three pre-processor statements accidentally did not start in column 1.
422        Sadly, there are *still* compilers around that complain, even though
423        standard C has not required this for well over a decade. Sigh.
424    
425     9. In pcretest, the code for checking callouts passed small integers in the
426        callout_data field, which is a void * field. However, some picky compilers
427        complained about the casts involved for this on 64-bit systems. Now
428        pcretest passes the address of the small integer instead, which should get
429        rid of the warnings.
430    
431    10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
432        both compile and run time, and gives an error if an invalid UTF-8 sequence
433        is found. There is a option for disabling this check in cases where the
434        string is known to be correct and/or the maximum performance is wanted.
435    
436    11. In response to a bug report, I changed one line in Makefile.in from
437    
438            -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
439        to
440            -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
441    
442        to look similar to other lines, but I have no way of telling whether this
443        is the right thing to do, as I do not use Windows. No doubt I'll get told
444        if it's wrong...
445    
446    
447  Version 4.3 21-May-03  Version 4.3 21-May-03
448  ---------------------  ---------------------
449    

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