/[pcre]/code/tags/pcre-8.01/ChangeLog
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revision 105 by ph10, Tue Mar 6 16:32:53 2007 UTC revision 256 by ph10, Wed Sep 19 08:57:53 2007 UTC
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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 7.1 05-Mar-07  Version 7.4 10-Sep-07
5  ---------------------  ---------------------
6    
7   1. Applied Bob Rossi and Daniel G's patches to convert the build system to one  1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
8      that is more "standard", making use of automake and other autotools. There      means that a class such as [\s] counted as "explicit reference to CR or
9        LF". That isn't really right - the whole point of the change was to try to
10        help when there was an actual mention of one of the two characters. So now
11        the change happens only if \r or \n (or a literal CR or LF) character is
12        encountered.
13    
14    2.  The 32-bit options word was also used for 6 internal flags, but the numbers
15        of both had grown to the point where there were only 3 bits left.
16        Fortunately, there was spare space in the data structure, and so I have
17        moved the internal flags into a new 16-bit field to free up more option
18        bits.
19    
20    3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
21        but did not set the internal JCHANGED flag - either of these is enough to
22        control the way the "get" function works - but the PCRE_INFO_JCHANGED
23        facility is supposed to tell if (?J) was ever used, so now (?J) at the
24        start sets both bits.
25    
26    4.  Added options (at build time, compile time, exec time) to change \R from
27        matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
28    
29    5.  doc/pcresyntax.html was missing from the distribution.
30    
31    6.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
32        compatibility, even though it is no longer used.
33    
34    7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
35        strtoull to pcrecpp.cc to select the available functions in WIN32 when the
36        windows.h file is present (where different names are used).
37    
38    8.  Changed all #include <config.h> to #include "config.h". There were also
39        some further <pcre.h> cases that I changed to "pcre.h".
40    
41    9.  When pcregrep was used with the --colour option, it missed the line ending
42        sequence off the lines that it output.
43    
44    10. It was pointed out to me that arrays of string pointers cause lots of
45        relocations when a shared library is dynamically loaded. A technique of
46        using a single long string with a table of offsets can drastically reduce
47        these. I have refactored PCRE in four places to do this. The result is
48        dramatic:
49    
50          Originally:                          290
51          After changing UCP table:            187
52          After changing error message table:   43
53          After changing table of "verbs"       36
54          After changing table of Posix names   22
55    
56        Thanks to the folks working on Gregex for glib for this insight.
57    
58    11. --disable-stack-for-recursion caused compiling to fail unless -enable-
59        unicode-properties was also set.
60    
61    12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
62    
63    13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
64        checked only for CRLF.
65    
66    14. Added casts to pcretest.c to avoid compiler warnings.
67    
68    15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
69    
70    
71    Version 7.3 28-Aug-07
72    ---------------------
73    
74     1. In the rejigging of the build system that eventually resulted in 7.1, the
75        line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
76        brackets there is not right, since it causes compilers to look for an
77        installed pcre.h, not the version that is in the source that is being
78        compiled (which of course may be different). I have changed it back to:
79    
80          #include "pcre.h"
81    
82        I have a vague recollection that the change was concerned with compiling in
83        different directories, but in the new build system, that is taken care of
84        by the VPATH setting the Makefile.
85    
86     2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
87        when the subject happened to end in the byte 0x85 (e.g. if the last
88        character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
89        characters but of course it shouldn't be taken as a newline when it is part
90        of another character. The bug was that, for an unlimited repeat of . in
91        not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
92        characters when looking for a newline.
93    
94     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
95    
96     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
97        in debug output.
98    
99     5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
100        long printing in the pcrecpp unittest when running under MinGW.
101    
102     6. ESC_K was left out of the EBCDIC table.
103    
104     7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
105        parentheses; I made it 1000, which seemed large enough. Unfortunately, the
106        limit also applies to "virtual nesting" when a pattern is recursive, and in
107        this case 1000 isn't so big. I have been able to remove this limit at the
108        expense of backing off one optimization in certain circumstances. Normally,
109        when pcre_exec() would call its internal match() function recursively and
110        immediately return the result unconditionally, it uses a "tail recursion"
111        feature to save stack. However, when a subpattern that can match an empty
112        string has an unlimited repetition quantifier, it no longer makes this
113        optimization. That gives it a stack frame in which to save the data for
114        checking that an empty string has been matched. Previously this was taken
115        from the 1000-entry workspace that had been reserved. So now there is no
116        explicit limit, but more stack is used.
117    
118     8. Applied Daniel's patches to solve problems with the import/export magic
119        syntax that is required for Windows, and which was going wrong for the
120        pcreposix and pcrecpp parts of the library. These were overlooked when this
121        problem was solved for the main library.
122    
123     9. There were some crude static tests to avoid integer overflow when computing
124        the size of patterns that contain repeated groups with explicit upper
125        limits. As the maximum quantifier is 65535, the maximum group length was
126        set at 30,000 so that the product of these two numbers did not overflow a
127        32-bit integer. However, it turns out that people want to use groups that
128        are longer than 30,000 bytes (though not repeat them that many times).
129        Change 7.0/17 (the refactoring of the way the pattern size is computed) has
130        made it possible to implement the integer overflow checks in a much more
131        dynamic way, which I have now done. The artificial limitation on group
132        length has been removed - we now have only the limit on the total length of
133        the compiled pattern, which depends on the LINK_SIZE setting.
134    
135    10. Fixed a bug in the documentation for get/copy named substring when
136        duplicate names are permitted. If none of the named substrings are set, the
137        functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
138        empty string.
139    
140    11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
141        instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
142        because the ] is interpreted as the first data character and the
143        terminating ] is not found. PCRE has been made compatible with Perl in this
144        regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
145        cause memory overwriting.
146    
147    10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
148        string has been matched (to stop an infinite loop). It was not recognizing
149        a conditional subpattern that could match an empty string if that
150        subpattern was within another subpattern. For example, it looped when
151        trying to match  (((?(1)X|))*)  but it was OK with  ((?(1)X|)*)  where the
152        condition was not nested. This bug has been fixed.
153    
154    12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
155        past the start of the subject in the presence of bytes with the top bit
156        set, for example "\x8aBCD".
157    
158    13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
159        (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
160    
161    14. Optimized (?!) to (*FAIL).
162    
163    15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
164        This restricts code points to be within the range 0 to 0x10FFFF, excluding
165        the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
166        full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
167        does: it's just the validity check that is more restrictive.
168    
169    16. Inserted checks for integer overflows during escape sequence (backslash)
170        processing, and also fixed erroneous offset values for syntax errors during
171        backslash processing.
172    
173    17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
174        for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
175    
176    18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
177        caused an overrun.
178    
179    19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
180        something other than just ASCII characters) inside a group that had an
181        unlimited repeat caused a loop at compile time (while checking to see
182        whether the group could match an empty string).
183    
184    20. Debugging a pattern containing \p or \P could cause a crash. For example,
185        [\P{Any}] did so. (Error in the code for printing property names.)
186    
187    21. An orphan \E inside a character class could cause a crash.
188    
189    22. A repeated capturing bracket such as (A)? could cause a wild memory
190        reference during compilation.
191    
192    23. There are several functions in pcre_compile() that scan along a compiled
193        expression for various reasons (e.g. to see if it's fixed length for look
194        behind). There were bugs in these functions when a repeated \p or \P was
195        present in the pattern. These operators have additional parameters compared
196        with \d, etc, and these were not being taken into account when moving along
197        the compiled data. Specifically:
198    
199        (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
200            length.
201    
202        (b) An item such as \pL+ within a repeated group could cause crashes or
203            loops.
204    
205        (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
206            "reference to non-existent subpattern" error.
207    
208        (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
209    
210    24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
211        characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
212    
213    25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
214    
215    26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
216        character were causing crashes (broken optimization).
217    
218    27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
219        \p or \P) caused a compile-time loop.
220    
221    28. More problems have arisen in unanchored patterns when CRLF is a valid line
222        break. For example, the unstudied pattern [\r\n]A does not match the string
223        "\r\nA" because change 7.0/46 below moves the current point on by two
224        characters after failing to match at the start. However, the pattern \nA
225        *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
226        the same is true. There doesn't seem any very clean way out of this, but
227        what I have chosen to do makes the common cases work: PCRE now takes note
228        of whether there can be an explicit match for \r or \n anywhere in the
229        pattern, and if so, 7.0/46 no longer applies. As part of this change,
230        there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
231        pattern has explicit CR or LF references.
232    
233    29. Added (*CR) etc for changing newline setting at start of pattern.
234    
235    
236    Version 7.2 19-Jun-07
237    ---------------------
238    
239     1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
240        which is apparently normally available under Windows.
241    
242     2. Re-jig the pcregrep tests with different newline settings in an attempt
243        to make them independent of the local environment's newline setting.
244    
245     3. Add code to configure.ac to remove -g from the CFLAGS default settings.
246    
247     4. Some of the "internals" tests were previously cut out when the link size
248        was not 2, because the output contained actual offsets. The recent new
249        "Z" feature of pcretest means that these can be cut out, making the tests
250        usable with all link sizes.
251    
252     5. Implemented Stan Switzer's goto replacement for longjmp() when not using
253        stack recursion. This gives a massive performance boost under BSD, but just
254        a small improvement under Linux. However, it saves one field in the frame
255        in all cases.
256    
257     6. Added more features from the forthcoming Perl 5.10:
258    
259        (a) (?-n) (where n is a string of digits) is a relative subroutine or
260            recursion call. It refers to the nth most recently opened parentheses.
261    
262        (b) (?+n) is also a relative subroutine call; it refers to the nth next
263            to be opened parentheses.
264    
265        (c) Conditions that refer to capturing parentheses can be specified
266            relatively, for example, (?(-2)... or (?(+3)...
267    
268        (d) \K resets the start of the current match so that everything before
269            is not part of it.
270    
271        (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
272    
273        (f) \g{name} is another synonym - part of Perl 5.10's unification of
274            reference syntax.
275    
276        (g) (?| introduces a group in which the numbering of parentheses in each
277            alternative starts with the same number.
278    
279        (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
280    
281     7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
282        PCRE_INFO_JCHANGED.
283    
284     8. A pattern such as  (.*(.)?)*  caused pcre_exec() to fail by either not
285        terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
286        for detecting groups that can match an empty string.
287    
288     9. A pattern with a very large number of alternatives (more than several
289        hundred) was running out of internal workspace during the pre-compile
290        phase, where pcre_compile() figures out how much memory will be needed. A
291        bit of new cunning has reduced the workspace needed for groups with
292        alternatives. The 1000-alternative test pattern now uses 12 bytes of
293        workspace instead of running out of the 4096 that are available.
294    
295    10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
296    
297    11. Applied patch from Google to remove an optimization that didn't quite work.
298        The report of the bug said:
299    
300          pcrecpp::RE("a*").FullMatch("aaa") matches, while
301          pcrecpp::RE("a*?").FullMatch("aaa") does not, and
302          pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
303    
304    12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
305        it matched the wrong number of bytes.
306    
307    
308    Version 7.1 24-Apr-07
309    ---------------------
310    
311     1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
312        that is more "standard", making use of automake and other Autotools. There
313      is some re-arrangement of the files and adjustment of comments consequent      is some re-arrangement of the files and adjustment of comments consequent
314      on this.      on this.
315    
316   2. Part of the patch fixed a problem with the pcregrep tests. The test of -r   2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
317      for recursive directory scanning broke on some systems because the files      for recursive directory scanning broke on some systems because the files
318      are not scanned in any specific order and on different systems the order      are not scanned in any specific order and on different systems the order
319      was different. A call to "sort" has been inserted into RunGrepTest for the      was different. A call to "sort" has been inserted into RunGrepTest for the
320      approprate test as a short-term fix. In the longer term there may be an      approprate test as a short-term fix. In the longer term there may be an
321      alternative.      alternative.
322    
323   3. I had an email from Eric Raymond about problems translating some of PCRE's   3. I had an email from Eric Raymond about problems translating some of PCRE's
324      man pages to HTML (despite the fact that I distribute HTML pages, some      man pages to HTML (despite the fact that I distribute HTML pages, some
325      people do their own conversions for various reasons). The problems      people do their own conversions for various reasons). The problems
326      concerned the use of low-level troff macros .br and .in. I have therefore      concerned the use of low-level troff macros .br and .in. I have therefore
327      removed all such uses from the man pages (some were redundant, some could      removed all such uses from the man pages (some were redundant, some could
328      be replaced by .nf/.fi pairs). The maintain/132html script that I use to      be replaced by .nf/.fi pairs). The 132html script that I use to generate
329      generate HTML has been updated to handle .nf/.fi and to complain if it      HTML has been updated to handle .nf/.fi and to complain if it encounters
330      encounters .br or .in.      .br or .in.
331    
332   4. Updated comments in configure.ac that get placed in config.h.in and also   4. Updated comments in configure.ac that get placed in config.h.in and also
333      arranged for config.h to be included in the distribution, for the benefit      arranged for config.h to be included in the distribution, with the name
334      of those who have to compile without Autotools (compare pcre.h).      config.h.generic, for the benefit of those who have to compile without
335        Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
336   5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan  
337      Weber: (1) pcre_internal.h was missing some function renames; (2) updated   5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
338      makevp.bat for the current PCRE, using the additional files !compile.txt,      Weber: (1) pcre_internal.h was missing some function renames; (2) updated
339      !linklib.txt, and pcregexp.pas.      makevp.bat for the current PCRE, using the additional files
340        makevp_c.txt, makevp_l.txt, and pcregexp.pas.
341   6. A Windows user reported a minor discrepancy with test 2, which turned out  
342      to be caused by a trailing space on an input line that had got lost in his   6. A Windows user reported a minor discrepancy with test 2, which turned out
343        to be caused by a trailing space on an input line that had got lost in his
344      copy. The trailing space was an accident, so I've just removed it.      copy. The trailing space was an accident, so I've just removed it.
345    
346   7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told   7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
347      that is needed.      that is needed.
348    
349   8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)   8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
350      as "const" (a) because they are and (b) because it helps the PHP      as "const" (a) because they are and (b) because it helps the PHP
351      maintainers who have recently made a script to detect big data structures      maintainers who have recently made a script to detect big data structures
352      in the php code that should be moved to the .rodata section. I remembered      in the php code that should be moved to the .rodata section. I remembered
353      to update Builducptable as well, so it won't revert if ucptable.h is ever      to update Builducptable as well, so it won't revert if ucptable.h is ever
354      re-created.      re-created.
355    
356     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
357        pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
358        order to be able to cut out the UTF-8 tables in the latter when UTF-8
359        support is not required. This saves 1.5-2K of code, which is important in
360        some applications.
361    
362        Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
363        so as not to refer to the tables, even though these functions will never be
364        called when UTF-8 support is disabled. Otherwise there are problems with a
365        shared library.
366    
367    10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
368    
369        (a) It was defining its arguments as char * instead of void *.
370    
371        (b) It was assuming that all moves were upwards in memory; this was true
372            a long time ago when I wrote it, but is no longer the case.
373    
374        The emulated memove() is provided for those environments that have neither
375        memmove() nor bcopy(). I didn't think anyone used it these days, but that
376        is clearly not the case, as these two bugs were recently reported.
377    
378    11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
379        and Detrail to create the HTML documentation, the .txt form of the man
380        pages, and it removes trailing spaces from listed files. It also creates
381        pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
382        case, it wraps all the #defines with #ifndefs. This script should be run
383        before "make dist".
384    
385    12. Fixed two fairly obscure bugs concerned with quantified caseless matching
386        with Unicode property support.
387    
388        (a) For a maximizing quantifier, if the two different cases of the
389            character were of different lengths in their UTF-8 codings (there are
390            some cases like this - I found 11), and the matching function had to
391            back up over a mixture of the two cases, it incorrectly assumed they
392            were both the same length.
393    
394        (b) When PCRE was configured to use the heap rather than the stack for
395            recursion during matching, it was not correctly preserving the data for
396            the other case of a UTF-8 character when checking ahead for a match
397            while processing a minimizing repeat. If the check also involved
398            matching a wide character, but failed, corruption could cause an
399            erroneous result when trying to check for a repeat of the original
400            character.
401    
402    13. Some tidying changes to the testing mechanism:
403    
404        (a) The RunTest script now detects the internal link size and whether there
405            is UTF-8 and UCP support by running ./pcretest -C instead of relying on
406            values substituted by "configure". (The RunGrepTest script already did
407            this for UTF-8.) The configure.ac script no longer substitutes the
408            relevant variables.
409    
410        (b) The debugging options /B and /D in pcretest show the compiled bytecode
411            with length and offset values. This means that the output is different
412            for different internal link sizes. Test 2 is skipped for link sizes
413            other than 2 because of this, bypassing the problem. Unfortunately,
414            there was also a test in test 3 (the locale tests) that used /B and
415            failed for link sizes other than 2. Rather than cut the whole test out,
416            I have added a new /Z option to pcretest that replaces the length and
417            offset values with spaces. This is now used to make test 3 independent
418            of link size. (Test 2 will be tidied up later.)
419    
420    14. If erroroffset was passed as NULL to pcre_compile, it provoked a
421        segmentation fault instead of returning the appropriate error message.
422    
423    15. In multiline mode when the newline sequence was set to "any", the pattern
424        ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
425        This doesn't seem right; it now treats the CRLF combination as the line
426        ending, and so does not match in that case. It's only a pattern such as ^$
427        that would hit this one: something like ^ABC$ would have failed after \r
428        and then tried again after \r\n.
429    
430    16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
431        in an attempt to make files that differ only in their line terminators
432        compare equal. This works on Linux.
433    
434    17. Under certain error circumstances pcregrep might try to free random memory
435        as it exited. This is now fixed, thanks to valgrind.
436    
437    19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
438        "abc\r\n\r\n", it found an unwanted second match after the second \r. This
439        was because its rules for how to advance for /g after matching an empty
440        string at the end of a line did not allow for this case. They now check for
441        it specially.
442    
443    20. pcretest is supposed to handle patterns and data of any length, by
444        extending its buffers when necessary. It was getting this wrong when the
445        buffer for a data line had to be extended.
446    
447    21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
448        CRLF as a newline sequence.
449    
450    22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
451        out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
452        I have nevertheless tidied it up.
453    
454    23. Added some casts to kill warnings from HP-UX ia64 compiler.
455    
456    24. Added a man page for pcre-config.
457    
458    
459  Version 7.0 19-Dec-06  Version 7.0 19-Dec-06
460  ---------------------  ---------------------

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