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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4    Version 7.5 12-Nov-07
5    ---------------------
6    
7    1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
8        values in parens when parsing an RE using the C++ wrapper."
9    
10    
11    Version 7.4 21-Sep-07
12    ---------------------
13    
14    1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
15        means that a class such as [\s] counted as "explicit reference to CR or
16        LF". That isn't really right - the whole point of the change was to try to
17        help when there was an actual mention of one of the two characters. So now
18        the change happens only if \r or \n (or a literal CR or LF) character is
19        encountered.
20    
21    2.  The 32-bit options word was also used for 6 internal flags, but the numbers
22        of both had grown to the point where there were only 3 bits left.
23        Fortunately, there was spare space in the data structure, and so I have
24        moved the internal flags into a new 16-bit field to free up more option
25        bits.
26    
27    3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
28        but did not set the internal JCHANGED flag - either of these is enough to
29        control the way the "get" function works - but the PCRE_INFO_JCHANGED
30        facility is supposed to tell if (?J) was ever used, so now (?J) at the
31        start sets both bits.
32    
33    4.  Added options (at build time, compile time, exec time) to change \R from
34        matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
35    
36    5.  doc/pcresyntax.html was missing from the distribution.
37    
38    6.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
39        compatibility, even though it is no longer used.
40    
41    7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
42        strtoull to pcrecpp.cc to select the available functions in WIN32 when the
43        windows.h file is present (where different names are used). [This was
44        reversed later after testing - see 16 below.]
45    
46    8.  Changed all #include <config.h> to #include "config.h". There were also
47        some further <pcre.h> cases that I changed to "pcre.h".
48    
49    9.  When pcregrep was used with the --colour option, it missed the line ending
50        sequence off the lines that it output.
51    
52    10. It was pointed out to me that arrays of string pointers cause lots of
53        relocations when a shared library is dynamically loaded. A technique of
54        using a single long string with a table of offsets can drastically reduce
55        these. I have refactored PCRE in four places to do this. The result is
56        dramatic:
57    
58          Originally:                          290
59          After changing UCP table:            187
60          After changing error message table:   43
61          After changing table of "verbs"       36
62          After changing table of Posix names   22
63    
64        Thanks to the folks working on Gregex for glib for this insight.
65    
66    11. --disable-stack-for-recursion caused compiling to fail unless -enable-
67        unicode-properties was also set.
68    
69    12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
70    
71    13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
72        checked only for CRLF.
73    
74    14. Added casts to pcretest.c to avoid compiler warnings.
75    
76    15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
77    
78    16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
79        and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
80        entirely. This removes changes made in 7 above.
81    
82    17. The CMake files have been updated, and there is now more information about
83        building with CMake in the NON-UNIX-USE document.
84    
85    
86    Version 7.3 28-Aug-07
87    ---------------------
88    
89     1. In the rejigging of the build system that eventually resulted in 7.1, the
90        line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
91        brackets there is not right, since it causes compilers to look for an
92        installed pcre.h, not the version that is in the source that is being
93        compiled (which of course may be different). I have changed it back to:
94    
95          #include "pcre.h"
96    
97        I have a vague recollection that the change was concerned with compiling in
98        different directories, but in the new build system, that is taken care of
99        by the VPATH setting the Makefile.
100    
101     2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
102        when the subject happened to end in the byte 0x85 (e.g. if the last
103        character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
104        characters but of course it shouldn't be taken as a newline when it is part
105        of another character. The bug was that, for an unlimited repeat of . in
106        not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
107        characters when looking for a newline.
108    
109     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
110    
111     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
112        in debug output.
113    
114     5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
115        long printing in the pcrecpp unittest when running under MinGW.
116    
117     6. ESC_K was left out of the EBCDIC table.
118    
119     7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
120        parentheses; I made it 1000, which seemed large enough. Unfortunately, the
121        limit also applies to "virtual nesting" when a pattern is recursive, and in
122        this case 1000 isn't so big. I have been able to remove this limit at the
123        expense of backing off one optimization in certain circumstances. Normally,
124        when pcre_exec() would call its internal match() function recursively and
125        immediately return the result unconditionally, it uses a "tail recursion"
126        feature to save stack. However, when a subpattern that can match an empty
127        string has an unlimited repetition quantifier, it no longer makes this
128        optimization. That gives it a stack frame in which to save the data for
129        checking that an empty string has been matched. Previously this was taken
130        from the 1000-entry workspace that had been reserved. So now there is no
131        explicit limit, but more stack is used.
132    
133     8. Applied Daniel's patches to solve problems with the import/export magic
134        syntax that is required for Windows, and which was going wrong for the
135        pcreposix and pcrecpp parts of the library. These were overlooked when this
136        problem was solved for the main library.
137    
138     9. There were some crude static tests to avoid integer overflow when computing
139        the size of patterns that contain repeated groups with explicit upper
140        limits. As the maximum quantifier is 65535, the maximum group length was
141        set at 30,000 so that the product of these two numbers did not overflow a
142        32-bit integer. However, it turns out that people want to use groups that
143        are longer than 30,000 bytes (though not repeat them that many times).
144        Change 7.0/17 (the refactoring of the way the pattern size is computed) has
145        made it possible to implement the integer overflow checks in a much more
146        dynamic way, which I have now done. The artificial limitation on group
147        length has been removed - we now have only the limit on the total length of
148        the compiled pattern, which depends on the LINK_SIZE setting.
149    
150    10. Fixed a bug in the documentation for get/copy named substring when
151        duplicate names are permitted. If none of the named substrings are set, the
152        functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
153        empty string.
154    
155    11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
156        instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
157        because the ] is interpreted as the first data character and the
158        terminating ] is not found. PCRE has been made compatible with Perl in this
159        regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
160        cause memory overwriting.
161    
162    10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
163        string has been matched (to stop an infinite loop). It was not recognizing
164        a conditional subpattern that could match an empty string if that
165        subpattern was within another subpattern. For example, it looped when
166        trying to match  (((?(1)X|))*)  but it was OK with  ((?(1)X|)*)  where the
167        condition was not nested. This bug has been fixed.
168    
169    12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
170        past the start of the subject in the presence of bytes with the top bit
171        set, for example "\x8aBCD".
172    
173    13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
174        (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
175    
176    14. Optimized (?!) to (*FAIL).
177    
178    15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
179        This restricts code points to be within the range 0 to 0x10FFFF, excluding
180        the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
181        full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
182        does: it's just the validity check that is more restrictive.
183    
184    16. Inserted checks for integer overflows during escape sequence (backslash)
185        processing, and also fixed erroneous offset values for syntax errors during
186        backslash processing.
187    
188    17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
189        for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
190    
191    18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
192        caused an overrun.
193    
194    19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
195        something other than just ASCII characters) inside a group that had an
196        unlimited repeat caused a loop at compile time (while checking to see
197        whether the group could match an empty string).
198    
199    20. Debugging a pattern containing \p or \P could cause a crash. For example,
200        [\P{Any}] did so. (Error in the code for printing property names.)
201    
202    21. An orphan \E inside a character class could cause a crash.
203    
204    22. A repeated capturing bracket such as (A)? could cause a wild memory
205        reference during compilation.
206    
207    23. There are several functions in pcre_compile() that scan along a compiled
208        expression for various reasons (e.g. to see if it's fixed length for look
209        behind). There were bugs in these functions when a repeated \p or \P was
210        present in the pattern. These operators have additional parameters compared
211        with \d, etc, and these were not being taken into account when moving along
212        the compiled data. Specifically:
213    
214        (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
215            length.
216    
217        (b) An item such as \pL+ within a repeated group could cause crashes or
218            loops.
219    
220        (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
221            "reference to non-existent subpattern" error.
222    
223        (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
224    
225    24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
226        characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
227    
228    25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
229    
230    26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
231        character were causing crashes (broken optimization).
232    
233    27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
234        \p or \P) caused a compile-time loop.
235    
236    28. More problems have arisen in unanchored patterns when CRLF is a valid line
237        break. For example, the unstudied pattern [\r\n]A does not match the string
238        "\r\nA" because change 7.0/46 below moves the current point on by two
239        characters after failing to match at the start. However, the pattern \nA
240        *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
241        the same is true. There doesn't seem any very clean way out of this, but
242        what I have chosen to do makes the common cases work: PCRE now takes note
243        of whether there can be an explicit match for \r or \n anywhere in the
244        pattern, and if so, 7.0/46 no longer applies. As part of this change,
245        there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
246        pattern has explicit CR or LF references.
247    
248    29. Added (*CR) etc for changing newline setting at start of pattern.
249    
250    
251    Version 7.2 19-Jun-07
252    ---------------------
253    
254     1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
255        which is apparently normally available under Windows.
256    
257     2. Re-jig the pcregrep tests with different newline settings in an attempt
258        to make them independent of the local environment's newline setting.
259    
260     3. Add code to configure.ac to remove -g from the CFLAGS default settings.
261    
262     4. Some of the "internals" tests were previously cut out when the link size
263        was not 2, because the output contained actual offsets. The recent new
264        "Z" feature of pcretest means that these can be cut out, making the tests
265        usable with all link sizes.
266    
267     5. Implemented Stan Switzer's goto replacement for longjmp() when not using
268        stack recursion. This gives a massive performance boost under BSD, but just
269        a small improvement under Linux. However, it saves one field in the frame
270        in all cases.
271    
272     6. Added more features from the forthcoming Perl 5.10:
273    
274        (a) (?-n) (where n is a string of digits) is a relative subroutine or
275            recursion call. It refers to the nth most recently opened parentheses.
276    
277        (b) (?+n) is also a relative subroutine call; it refers to the nth next
278            to be opened parentheses.
279    
280        (c) Conditions that refer to capturing parentheses can be specified
281            relatively, for example, (?(-2)... or (?(+3)...
282    
283        (d) \K resets the start of the current match so that everything before
284            is not part of it.
285    
286        (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
287    
288        (f) \g{name} is another synonym - part of Perl 5.10's unification of
289            reference syntax.
290    
291        (g) (?| introduces a group in which the numbering of parentheses in each
292            alternative starts with the same number.
293    
294        (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
295    
296     7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
297        PCRE_INFO_JCHANGED.
298    
299     8. A pattern such as  (.*(.)?)*  caused pcre_exec() to fail by either not
300        terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
301        for detecting groups that can match an empty string.
302    
303     9. A pattern with a very large number of alternatives (more than several
304        hundred) was running out of internal workspace during the pre-compile
305        phase, where pcre_compile() figures out how much memory will be needed. A
306        bit of new cunning has reduced the workspace needed for groups with
307        alternatives. The 1000-alternative test pattern now uses 12 bytes of
308        workspace instead of running out of the 4096 that are available.
309    
310    10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
311    
312    11. Applied patch from Google to remove an optimization that didn't quite work.
313        The report of the bug said:
314    
315          pcrecpp::RE("a*").FullMatch("aaa") matches, while
316          pcrecpp::RE("a*?").FullMatch("aaa") does not, and
317          pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
318    
319    12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
320        it matched the wrong number of bytes.
321    
322    
323    Version 7.1 24-Apr-07
324    ---------------------
325    
326     1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
327        that is more "standard", making use of automake and other Autotools. There
328        is some re-arrangement of the files and adjustment of comments consequent
329        on this.
330    
331     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
332        for recursive directory scanning broke on some systems because the files
333        are not scanned in any specific order and on different systems the order
334        was different. A call to "sort" has been inserted into RunGrepTest for the
335        approprate test as a short-term fix. In the longer term there may be an
336        alternative.
337    
338     3. I had an email from Eric Raymond about problems translating some of PCRE's
339        man pages to HTML (despite the fact that I distribute HTML pages, some
340        people do their own conversions for various reasons). The problems
341        concerned the use of low-level troff macros .br and .in. I have therefore
342        removed all such uses from the man pages (some were redundant, some could
343        be replaced by .nf/.fi pairs). The 132html script that I use to generate
344        HTML has been updated to handle .nf/.fi and to complain if it encounters
345        .br or .in.
346    
347     4. Updated comments in configure.ac that get placed in config.h.in and also
348        arranged for config.h to be included in the distribution, with the name
349        config.h.generic, for the benefit of those who have to compile without
350        Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
351    
352     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
353        Weber: (1) pcre_internal.h was missing some function renames; (2) updated
354        makevp.bat for the current PCRE, using the additional files
355        makevp_c.txt, makevp_l.txt, and pcregexp.pas.
356    
357     6. A Windows user reported a minor discrepancy with test 2, which turned out
358        to be caused by a trailing space on an input line that had got lost in his
359        copy. The trailing space was an accident, so I've just removed it.
360    
361     7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
362        that is needed.
363    
364     8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
365        as "const" (a) because they are and (b) because it helps the PHP
366        maintainers who have recently made a script to detect big data structures
367        in the php code that should be moved to the .rodata section. I remembered
368        to update Builducptable as well, so it won't revert if ucptable.h is ever
369        re-created.
370    
371     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
372        pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
373        order to be able to cut out the UTF-8 tables in the latter when UTF-8
374        support is not required. This saves 1.5-2K of code, which is important in
375        some applications.
376    
377        Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
378        so as not to refer to the tables, even though these functions will never be
379        called when UTF-8 support is disabled. Otherwise there are problems with a
380        shared library.
381    
382    10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
383    
384        (a) It was defining its arguments as char * instead of void *.
385    
386        (b) It was assuming that all moves were upwards in memory; this was true
387            a long time ago when I wrote it, but is no longer the case.
388    
389        The emulated memove() is provided for those environments that have neither
390        memmove() nor bcopy(). I didn't think anyone used it these days, but that
391        is clearly not the case, as these two bugs were recently reported.
392    
393    11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
394        and Detrail to create the HTML documentation, the .txt form of the man
395        pages, and it removes trailing spaces from listed files. It also creates
396        pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
397        case, it wraps all the #defines with #ifndefs. This script should be run
398        before "make dist".
399    
400    12. Fixed two fairly obscure bugs concerned with quantified caseless matching
401        with Unicode property support.
402    
403        (a) For a maximizing quantifier, if the two different cases of the
404            character were of different lengths in their UTF-8 codings (there are
405            some cases like this - I found 11), and the matching function had to
406            back up over a mixture of the two cases, it incorrectly assumed they
407            were both the same length.
408    
409        (b) When PCRE was configured to use the heap rather than the stack for
410            recursion during matching, it was not correctly preserving the data for
411            the other case of a UTF-8 character when checking ahead for a match
412            while processing a minimizing repeat. If the check also involved
413            matching a wide character, but failed, corruption could cause an
414            erroneous result when trying to check for a repeat of the original
415            character.
416    
417    13. Some tidying changes to the testing mechanism:
418    
419        (a) The RunTest script now detects the internal link size and whether there
420            is UTF-8 and UCP support by running ./pcretest -C instead of relying on
421            values substituted by "configure". (The RunGrepTest script already did
422            this for UTF-8.) The configure.ac script no longer substitutes the
423            relevant variables.
424    
425        (b) The debugging options /B and /D in pcretest show the compiled bytecode
426            with length and offset values. This means that the output is different
427            for different internal link sizes. Test 2 is skipped for link sizes
428            other than 2 because of this, bypassing the problem. Unfortunately,
429            there was also a test in test 3 (the locale tests) that used /B and
430            failed for link sizes other than 2. Rather than cut the whole test out,
431            I have added a new /Z option to pcretest that replaces the length and
432            offset values with spaces. This is now used to make test 3 independent
433            of link size. (Test 2 will be tidied up later.)
434    
435    14. If erroroffset was passed as NULL to pcre_compile, it provoked a
436        segmentation fault instead of returning the appropriate error message.
437    
438    15. In multiline mode when the newline sequence was set to "any", the pattern
439        ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
440        This doesn't seem right; it now treats the CRLF combination as the line
441        ending, and so does not match in that case. It's only a pattern such as ^$
442        that would hit this one: something like ^ABC$ would have failed after \r
443        and then tried again after \r\n.
444    
445    16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
446        in an attempt to make files that differ only in their line terminators
447        compare equal. This works on Linux.
448    
449    17. Under certain error circumstances pcregrep might try to free random memory
450        as it exited. This is now fixed, thanks to valgrind.
451    
452    19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
453        "abc\r\n\r\n", it found an unwanted second match after the second \r. This
454        was because its rules for how to advance for /g after matching an empty
455        string at the end of a line did not allow for this case. They now check for
456        it specially.
457    
458    20. pcretest is supposed to handle patterns and data of any length, by
459        extending its buffers when necessary. It was getting this wrong when the
460        buffer for a data line had to be extended.
461    
462    21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
463        CRLF as a newline sequence.
464    
465    22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
466        out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
467        I have nevertheless tidied it up.
468    
469    23. Added some casts to kill warnings from HP-UX ia64 compiler.
470    
471    24. Added a man page for pcre-config.
472    
473    
474  Version 7.0 19-Dec-06  Version 7.0 19-Dec-06
475  ---------------------  ---------------------
476    

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