--- code/trunk/ChangeLog 2009/08/17 14:48:48 425 +++ code/trunk/ChangeLog 2010/03/02 11:53:12 494 @@ -1,46 +1,312 @@ ChangeLog for PCRE ------------------ -Version 8.00 ??-???-?? +Version 8.02 01-Mar-2010 +------------------------ + +1. The Unicode data tables have been updated to Unicode 5.2.0. + +2. Added the option --libs-cpp to pcre-config, but only when C++ support is + configured. + +3. Updated the licensing terms in the pcregexp.pas file, as agreed with the + original author of that file, following a query about its status. + +4. On systems that do not have stdint.h (e.g. Solaris), check for and include + inttypes.h instead. This fixes a bug that was introduced by change 8.01/8. + + +Version 8.01 19-Jan-2010 +------------------------ + +1. If a pattern contained a conditional subpattern with only one branch (in + particular, this includes all (*DEFINE) patterns), a call to pcre_study() + computed the wrong minimum data length (which is of course zero for such + subpatterns). This could cause incorrect "no match" results. + +2. For patterns such as (?i)a(?-i)b|c where an option setting at the start of + the pattern is reset in the first branch, pcre_compile() failed with + "internal error: code overflow at offset...". This happened only when + the reset was to the original external option setting. (An optimization + abstracts leading options settings into an external setting, which was the + cause of this.) + +3. A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one + of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the + assertion pattern did not match (meaning that the assertion was true), it + was incorrectly treated as false if the SKIP had been reached during the + matching. This also applied to assertions used as conditions. + +4. If an item that is not supported by pcre_dfa_exec() was encountered in an + assertion subpattern, including such a pattern used as a condition, + unpredictable results occurred, instead of the error return + PCRE_ERROR_DFA_UITEM. + +5. The C++ GlobalReplace function was not working like Perl for the special + situation when an empty string is matched. It now does the fancy magic + stuff that is necessary. + +6. In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been + removed. (These were left over from very, very early versions of PCRE.) + +7. Some cosmetic changes to the code to make life easier when compiling it + as part of something else: + + (a) Change DEBUG to PCRE_DEBUG. + + (b) In pcre_compile(), rename the member of the "branch_chain" structure + called "current" as "current_branch", to prevent a collision with the + Linux macro when compiled as a kernel module. + + (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to + prevent a collision with the Linux macro when compiled as a kernel + module. + +8. In pcre_compile() there are some checks for integer overflows that used to + cast potentially large values to (double). This has been changed to that + when building, a check for int64_t is made, and if it is found, it is used + instead, thus avoiding the use of floating point arithmetic. (There is no + other use of FP in PCRE.) If int64_t is not found, the fallback is to + double. + +9. Added two casts to avoid signed/unsigned warnings from VS Studio Express + 2005 (difference between two addresses compared to an unsigned value). + +10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a + custom one, because of the following reported problem in Windows: + + - libbz2 uses the Pascal calling convention (WINAPI) for the functions + under Win32. + - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h", + therefore missing the function definition. + - The compiler thus generates a "C" signature for the test function. + - The linker fails to find the "C" function. + - PCRE fails to configure if asked to do so against libbz2. + +11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these + messages were output: + + Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and + rerunning libtoolize, to keep the correct libtool macros in-tree. + Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am. + + I have done both of these things. + +12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec() + most of the time, it *can* run out if it is given a pattern that contains a + runaway infinite recursion. I updated the discussion in the pcrestack man + page. + +13. Now that we have gone to the x.xx style of version numbers, the minor + version may start with zero. Using 08 or 09 is a bad idea because users + might check the value of PCRE_MINOR in their code, and 08 or 09 may be + interpreted as invalid octal numbers. I've updated the previous comment in + configure.ac, and also added a check that gives an error if 08 or 09 are + used. + +14. Change 8.00/11 was not quite complete: code had been accidentally omitted, + causing partial matching to fail when the end of the subject matched \W + in a UTF-8 pattern where \W was quantified with a minimum of 3. + +15. There were some discrepancies between the declarations in pcre_internal.h + of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and + their definitions. The declarations used "const uschar *" and the + definitions used USPTR. Even though USPTR is normally defined as "const + unsigned char *" (and uschar is typedeffed as "unsigned char"), it was + reported that: "This difference in casting confuses some C++ compilers, for + example, SunCC recognizes above declarations as different functions and + generates broken code for hbpcre." I have changed the declarations to use + USPTR. + +16. GNU libtool is named differently on some systems. The autogen.sh script now + tries several variants such as glibtoolize (MacOSX) and libtoolize1x + (FreeBSD). + +17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00 + (strtoXX undefined when compiling pcrecpp.cc). The patch contains this + comment: "Figure out how to create a longlong from a string: strtoll and + equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for + instance, but it only takes 2 args instead of 3!" + +18. A subtle bug concerned with back references has been fixed by a change of + specification, with a corresponding code fix. A pattern such as + ^(xa|=?\1a)+$ which contains a back reference inside the group to which it + refers, was giving matches when it shouldn't. For example, xa=xaaa would + match that pattern. Interestingly, Perl (at least up to 5.11.3) has the + same bug. Such groups have to be quantified to be useful, or contained + inside another quantified group. (If there's no repetition, the reference + can never match.) The problem arises because, having left the group and + moved on to the rest of the pattern, a later failure that backtracks into + the group uses the captured value from the final iteration of the group + rather than the correct earlier one. I have fixed this in PCRE by forcing + any group that contains a reference to itself to be an atomic group; that + is, there cannot be any backtracking into it once it has completed. This is + similar to recursive and subroutine calls. + + +Version 8.00 19-Oct-09 ---------------------- 1. The table for translating pcre_compile() error codes into POSIX error codes - was out-of-date, and there was no check on the pcre_compile() error code - being within the table. This could lead to an OK return being given in + was out-of-date, and there was no check on the pcre_compile() error code + being within the table. This could lead to an OK return being given in error. - -2. Changed the call to open a subject file in pcregrep from fopen(pathname, - "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests - in a Windows environment. - + +2. Changed the call to open a subject file in pcregrep from fopen(pathname, + "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests + in a Windows environment. + 3. The pcregrep --count option prints the count for each file even when it is zero, as does GNU grep. However, pcregrep was also printing all files when --files-with-matches was added. Now, when both options are given, it prints counts only for those files that have at least one match. (GNU grep just - prints the file name in this circumstance, but including the count seems - more useful - otherwise, why use --count?) Also ensured that the + prints the file name in this circumstance, but including the count seems + more useful - otherwise, why use --count?) Also ensured that the combination -clh just lists non-zero counts, with no names. - -4. The long form of the pcregrep -F option was incorrectly implemented as - --fixed_strings instead of --fixed-strings. This is an incompatible change, - but it seems right to fix it, and I didn't think it was worth preserving - the old behaviour. - -5. The command line items --regex=pattern and --regexp=pattern were not + +4. The long form of the pcregrep -F option was incorrectly implemented as + --fixed_strings instead of --fixed-strings. This is an incompatible change, + but it seems right to fix it, and I didn't think it was worth preserving + the old behaviour. + +5. The command line items --regex=pattern and --regexp=pattern were not recognized by pcregrep, which required --regex pattern or --regexp pattern - (with a space rather than an '='). The man page documented the '=' forms, + (with a space rather than an '='). The man page documented the '=' forms, which are compatible with GNU grep; these now work. - -6. No libpcreposix.pc file was created for pkg-config; there was just + +6. No libpcreposix.pc file was created for pkg-config; there was just libpcre.pc and libpcrecpp.pc. The omission has been rectified. - + 7. Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size - when UCP support is not needed, by modifying the Python script that + when UCP support is not needed, by modifying the Python script that generates it from Unicode data files. This should not matter if the module is correctly used as a library, but I received one complaint about 50K of unwanted data. My guess is that the person linked everything into his program rather than using a library. Anyway, it does no harm. - + +8. A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger + was a minimum greater than 1 for a wide character in a possessive + repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8 + which had an unlimited repeat of a nested, fixed maximum repeat of a wide + character. Chaos in the form of incorrect output or a compiling loop could + result. + +9. The restrictions on what a pattern can contain when partial matching is + requested for pcre_exec() have been removed. All patterns can now be + partially matched by this function. In addition, if there are at least two + slots in the offset vector, the offset of the earliest inspected character + for the match and the offset of the end of the subject are set in them when + PCRE_ERROR_PARTIAL is returned. + +10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is + synonymous with PCRE_PARTIAL, for backwards compatibility, and + PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match, + and may be more useful for multi-segment matching. + +11. Partial matching with pcre_exec() is now more intuitive. A partial match + used to be given if ever the end of the subject was reached; now it is + given only if matching could not proceed because another character was + needed. This makes a difference in some odd cases such as Z(*FAIL) with the + string "Z", which now yields "no match" instead of "partial match". In the + case of pcre_dfa_exec(), "no match" is given if every matching path for the + final character ended with (*FAIL). + +12. Restarting a match using pcre_dfa_exec() after a partial match did not work + if the pattern had a "must contain" character that was already found in the + earlier partial match, unless partial matching was again requested. For + example, with the pattern /dog.(body)?/, the "must contain" character is + "g". If the first part-match was for the string "dog", restarting with + "sbody" failed. This bug has been fixed. + +13. The string returned by pcre_dfa_exec() after a partial match has been + changed so that it starts at the first inspected character rather than the + first character of the match. This makes a difference only if the pattern + starts with a lookbehind assertion or \b or \B (\K is not supported by + pcre_dfa_exec()). It's an incompatible change, but it makes the two + matching functions compatible, and I think it's the right thing to do. + +14. Added a pcredemo man page, created automatically from the pcredemo.c file, + so that the demonstration program is easily available in environments where + PCRE has not been installed from source. + +15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp, + libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared + library. + +16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user. + It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it + is not the first non-POSIX option to be added. Clearly some people find + these options useful. + +17. If a caller to the POSIX matching function regexec() passes a non-zero + value for nmatch with a NULL value for pmatch, the value of + nmatch is forced to zero. + +18. RunGrepTest did not have a test for the availability of the -u option of + the diff command, as RunTest does. It now checks in the same way as + RunTest, and also checks for the -b option. + +19. If an odd number of negated classes containing just a single character + interposed, within parentheses, between a forward reference to a named + subpattern and the definition of the subpattern, compilation crashed with + an internal error, complaining that it could not find the referenced + subpattern. An example of a crashing pattern is /(?&A)(([^m])(?))/. + [The bug was that it was starting one character too far in when skipping + over the character class, thus treating the ] as data rather than + terminating the class. This meant it could skip too much.] + +20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the + /g option in pcretest when the pattern contains \K, which makes it possible + to have an empty string match not at the start, even when the pattern is + anchored. Updated pcretest and pcredemo to use this option. + +21. If the maximum number of capturing subpatterns in a recursion was greater + than the maximum at the outer level, the higher number was returned, but + with unset values at the outer level. The correct (outer level) value is + now given. + +22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of + PCRE did not set those parentheses (unlike Perl). I have now found a way to + make it do so. The string so far is captured, making this feature + compatible with Perl. + +23. The tests have been re-organized, adding tests 11 and 12, to make it + possible to check the Perl 5.10 features against Perl 5.10. + +24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine + pattern matches a fixed length string. PCRE did not allow this; now it + does. Neither allows recursion. + +25. I finally figured out how to implement a request to provide the minimum + length of subject string that was needed in order to match a given pattern. + (It was back references and recursion that I had previously got hung up + on.) This code has now been added to pcre_study(); it finds a lower bound + to the length of subject needed. It is not necessarily the greatest lower + bound, but using it to avoid searching strings that are too short does give + some useful speed-ups. The value is available to calling programs via + pcre_fullinfo(). + +26. While implementing 25, I discovered to my embarrassment that pcretest had + not been passing the result of pcre_study() to pcre_dfa_exec(), so the + study optimizations had never been tested with that matching function. + Oops. What is worse, even when it was passed study data, there was a bug in + pcre_dfa_exec() that meant it never actually used it. Double oops. There + were also very few tests of studied patterns with pcre_dfa_exec(). + +27. If (?| is used to create subpatterns with duplicate numbers, they are now + allowed to have the same name, even if PCRE_DUPNAMES is not set. However, + on the other side of the coin, they are no longer allowed to have different + names, because these cannot be distinguished in PCRE, and this has caused + confusion. (This is a difference from Perl.) + +28. When duplicate subpattern names are present (necessarily with different + numbers, as required by 27 above), and a test is made by name in a + conditional pattern, either for a subpattern having been matched, or for + recursion in such a pattern, all the associated numbered subpatterns are + tested, and the overall condition is true if the condition is true for any + one of them. This is the way Perl works, and is also more like the way + testing by number works. + Version 7.9 11-Apr-09 ---------------------