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diff --git a/pcre/ChangeLog b/pcre/ChangeLog new file mode 100644 index 00000000000..21cada49c9e --- /dev/null +++ b/pcre/ChangeLog @@ -0,0 +1,5149 @@ +ChangeLog for PCRE +------------------ + +Version 8.33 28-May-2013 +-------------------------- + +1. Added 'U' to some constants that are compared to unsigned integers, to + avoid compiler signed/unsigned warnings. Added (int) casts to unsigned + variables that are added to signed variables, to ensure the result is + signed and can be negated. + +2. Applied patch by Daniel Richard G for quashing MSVC warnings to the + CMake config files. + +3. Revise the creation of config.h.generic so that all boolean macros are + #undefined, whereas non-boolean macros are #ifndef/#endif-ed. This makes + overriding via -D on the command line possible. + +4. Changing the definition of the variable "op" in pcre_exec.c from pcre_uchar + to unsigned int is reported to make a quite noticeable speed difference in + a specific Windows environment. Testing on Linux did also appear to show + some benefit (and it is clearly not harmful). Also fixed the definition of + Xop which should be unsigned. + +5. Related to (4), changing the definition of the intermediate variable cc + in repeated character loops from pcre_uchar to pcre_uint32 also gave speed + improvements. + +6. Fix forward search in JIT when link size is 3 or greater. Also removed some + unnecessary spaces. + +7. Adjust autogen.sh and configure.ac to lose warnings given by automake 1.12 + and later. + +8. Fix two buffer over read issues in 16 and 32 bit modes. Affects JIT only. + +9. Optimizing fast_forward_start_bits in JIT. + +10. Adding support for callouts in JIT, and fixing some issues revealed + during this work. Namely: + + (a) Unoptimized capturing brackets incorrectly reset on backtrack. + + (b) Minimum length was not checked before the matching is started. + +11. The value of capture_last that is passed to callouts was incorrect in some + cases when there was a capture on one path that was subsequently abandoned + after a backtrack. Also, the capture_last value is now reset after a + recursion, since all captures are also reset in this case. + +12. The interpreter no longer returns the "too many substrings" error in the + case when an overflowing capture is in a branch that is subsequently + abandoned after a backtrack. + +13. In the pathological case when an offset vector of size 2 is used, pcretest + now prints out the matched string after a yield of 0 or 1. + +14. Inlining subpatterns in recursions, when certain conditions are fulfilled. + Only supported by the JIT compiler at the moment. + +15. JIT compiler now supports 32 bit Macs thanks to Lawrence Velazquez. + +16. Partial matches now set offsets[2] to the "bumpalong" value, that is, the + offset of the starting point of the matching process, provided the offsets + vector is large enough. + +17. The \A escape now records a lookbehind value of 1, though its execution + does not actually inspect the previous character. This is to ensure that, + in partial multi-segment matching, at least one character from the old + segment is retained when a new segment is processed. Otherwise, if there + are no lookbehinds in the pattern, \A might match incorrectly at the start + of a new segment. + +18. Added some #ifdef __VMS code into pcretest.c to help VMS implementations. + +19. Redefined some pcre_uchar variables in pcre_exec.c as pcre_uint32; this + gives some modest performance improvement in 8-bit mode. + +20. Added the PCRE-specific property \p{Xuc} for matching characters that can + be expressed in certain programming languages using Universal Character + Names. + +21. Unicode validation has been updated in the light of Unicode Corrigendum #9, + which points out that "non characters" are not "characters that may not + appear in Unicode strings" but rather "characters that are reserved for + internal use and have only local meaning". + +22. When a pattern was compiled with automatic callouts (PCRE_AUTO_CALLOUT) and + there was a conditional group that depended on an assertion, if the + assertion was false, the callout that immediately followed the alternation + in the condition was skipped when pcre_exec() was used for matching. + +23. Allow an explicit callout to be inserted before an assertion that is the + condition for a conditional group, for compatibility with automatic + callouts, which always insert a callout at this point. + +24. In 8.31, (*COMMIT) was confined to within a recursive subpattern. Perl also + confines (*SKIP) and (*PRUNE) in the same way, and this has now been done. + +25. (*PRUNE) is now supported by the JIT compiler. + +26. Fix infinite loop when /(?<=(*SKIP)ac)a/ is matched against aa. + +27. Fix the case where there are two or more SKIPs with arguments that may be + ignored. + +28. (*SKIP) is now supported by the JIT compiler. + +29. (*THEN) is now supported by the JIT compiler. + +30. Update RunTest with additional test selector options. + +31. The way PCRE handles backtracking verbs has been changed in two ways. + + (1) Previously, in something like (*COMMIT)(*SKIP), COMMIT would override + SKIP. Now, PCRE acts on whichever backtracking verb is reached first by + backtracking. In some cases this makes it more Perl-compatible, but Perl's + rather obscure rules do not always do the same thing. + + (2) Previously, backtracking verbs were confined within assertions. This is + no longer the case for positive assertions, except for (*ACCEPT). Again, + this sometimes improves Perl compatibility, and sometimes does not. + +32. A number of tests that were in test 2 because Perl did things differently + have been moved to test 1, because either Perl or PCRE has changed, and + these tests are now compatible. + +32. Backtracking control verbs are now handled in the same way in JIT and + interpreter. + +33. An opening parenthesis in a MARK/PRUNE/SKIP/THEN name in a pattern that + contained a forward subroutine reference caused a compile error. + +34. Auto-detect and optimize limited repetitions in JIT. + +35. Implement PCRE_NEVER_UTF to lock out the use of UTF, in particular, + blocking (*UTF) etc. + +36. In the interpreter, maximizing pattern repetitions for characters and + character types now use tail recursion, which reduces stack usage. + +37. The value of the max lookbehind was not correctly preserved if a compiled + and saved regex was reloaded on a host of different endianness. + +38. Implemented (*LIMIT_MATCH) and (*LIMIT_RECURSION). As part of the extension + of the compiled pattern block, expand the flags field from 16 to 32 bits + because it was almost full. + +39. Try madvise first before posix_madvise. + +40. Change 7 for PCRE 7.9 made it impossible for pcregrep to find empty lines + with a pattern such as ^$. It has taken 4 years for anybody to notice! The + original change locked out all matches of empty strings. This has been + changed so that one match of an empty string per line is recognized. + Subsequent searches on the same line (for colouring or for --only-matching, + for example) do not recognize empty strings. + +41. Applied a user patch to fix a number of spelling mistakes in comments. + +42. Data lines longer than 65536 caused pcretest to crash. + +43. Clarified the data type for length and startoffset arguments for pcre_exec + and pcre_dfa_exec in the function-specific man pages, where they were + explicitly stated to be in bytes, never having been updated. I also added + some clarification to the pcreapi man page. + +44. A call to pcre_dfa_exec() with an output vector size less than 2 caused + a segmentation fault. + + +Version 8.32 30-November-2012 +----------------------------- + +1. Improved JIT compiler optimizations for first character search and single + character iterators. + +2. Supporting IBM XL C compilers for PPC architectures in the JIT compiler. + Patch by Daniel Richard G. + +3. Single character iterator optimizations in the JIT compiler. + +4. Improved JIT compiler optimizations for character ranges. + +5. Rename the "leave" variable names to "quit" to improve WinCE compatibility. + Reported by Giuseppe D'Angelo. + +6. The PCRE_STARTLINE bit, indicating that a match can occur only at the start + of a line, was being set incorrectly in cases where .* appeared inside + atomic brackets at the start of a pattern, or where there was a subsequent + *PRUNE or *SKIP. + +7. Improved instruction cache flush for POWER/PowerPC. + Patch by Daniel Richard G. + +8. Fixed a number of issues in pcregrep, making it more compatible with GNU + grep: + + (a) There is now no limit to the number of patterns to be matched. + + (b) An error is given if a pattern is too long. + + (c) Multiple uses of --exclude, --exclude-dir, --include, and --include-dir + are now supported. + + (d) --exclude-from and --include-from (multiple use) have been added. + + (e) Exclusions and inclusions now apply to all files and directories, not + just to those obtained from scanning a directory recursively. + + (f) Multiple uses of -f and --file-list are now supported. + + (g) In a Windows environment, the default for -d has been changed from + "read" (the GNU grep default) to "skip", because otherwise the presence + of a directory in the file list provokes an error. + + (h) The documentation has been revised and clarified in places. + +9. Improve the matching speed of capturing brackets. + +10. Changed the meaning of \X so that it now matches a Unicode extended + grapheme cluster. + +11. Patch by Daniel Richard G to the autoconf files to add a macro for sorting + out POSIX threads when JIT support is configured. + +12. Added support for PCRE_STUDY_EXTRA_NEEDED. + +13. In the POSIX wrapper regcomp() function, setting re_nsub field in the preg + structure could go wrong in environments where size_t is not the same size + as int. + +14. Applied user-supplied patch to pcrecpp.cc to allow PCRE_NO_UTF8_CHECK to be + set. + +15. The EBCDIC support had decayed; later updates to the code had included + explicit references to (e.g.) \x0a instead of CHAR_LF. There has been a + general tidy up of EBCDIC-related issues, and the documentation was also + not quite right. There is now a test that can be run on ASCII systems to + check some of the EBCDIC-related things (but is it not a full test). + +16. The new PCRE_STUDY_EXTRA_NEEDED option is now used by pcregrep, resulting + in a small tidy to the code. + +17. Fix JIT tests when UTF is disabled and both 8 and 16 bit mode are enabled. + +18. If the --only-matching (-o) option in pcregrep is specified multiple + times, each one causes appropriate output. For example, -o1 -o2 outputs the + substrings matched by the 1st and 2nd capturing parentheses. A separating + string can be specified by --om-separator (default empty). + +19. Improving the first n character searches. + +20. Turn case lists for horizontal and vertical white space into macros so that + they are defined only once. + +21. This set of changes together give more compatible Unicode case-folding + behaviour for characters that have more than one other case when UCP + support is available. + + (a) The Unicode property table now has offsets into a new table of sets of + three or more characters that are case-equivalent. The MultiStage2.py + script that generates these tables (the pcre_ucd.c file) now scans + CaseFolding.txt instead of UnicodeData.txt for character case + information. + + (b) The code for adding characters or ranges of characters to a character + class has been abstracted into a generalized function that also handles + case-independence. In UTF-mode with UCP support, this uses the new data + to handle characters with more than one other case. + + (c) A bug that is fixed as a result of (b) is that codepoints less than 256 + whose other case is greater than 256 are now correctly matched + caselessly. Previously, the high codepoint matched the low one, but not + vice versa. + + (d) The processing of \h, \H, \v, and \ in character classes now makes use + of the new class addition function, using character lists defined as + macros alongside the case definitions of 20 above. + + (e) Caseless back references now work with characters that have more than + one other case. + + (f) General caseless matching of characters with more than one other case + is supported. + +22. Unicode character properties were updated from Unicode 6.2.0 + +23. Improved CMake support under Windows. Patch by Daniel Richard G. + +24. Add support for 32-bit character strings, and UTF-32 + +25. Major JIT compiler update (code refactoring and bugfixing). + Experimental Sparc 32 support is added. + +26. Applied a modified version of Daniel Richard G's patch to create + pcre.h.generic and config.h.generic by "make" instead of in the + PrepareRelease script. + +27. Added a definition for CHAR_NULL (helpful for the z/OS port), and use it in + pcre_compile.c when checking for a zero character. + +28. Introducing a native interface for JIT. Through this interface, the compiled + machine code can be directly executed. The purpose of this interface is to + provide fast pattern matching, so several sanity checks are not performed. + However, feature tests are still performed. The new interface provides + 1.4x speedup compared to the old one. + +29. If pcre_exec() or pcre_dfa_exec() was called with a negative value for + the subject string length, the error given was PCRE_ERROR_BADOFFSET, which + was confusing. There is now a new error PCRE_ERROR_BADLENGTH for this case. + +30. In 8-bit UTF-8 mode, pcretest failed to give an error for data codepoints + greater than 0x7fffffff (which cannot be represented in UTF-8, even under + the "old" RFC 2279). Instead, it ended up passing a negative length to + pcre_exec(). + +31. Add support for GCC's visibility feature to hide internal functions. + +32. Running "pcretest -C pcre8" or "pcretest -C pcre16" gave a spurious error + "unknown -C option" after outputting 0 or 1. + +33. There is now support for generating a code coverage report for the test + suite in environments where gcc is the compiler and lcov is installed. This + is mainly for the benefit of the developers. + +34. If PCRE is built with --enable-valgrind, certain memory regions are marked + unaddressable using valgrind annotations, allowing valgrind to detect + invalid memory accesses. This is mainly for the benefit of the developers. + +25. (*UTF) can now be used to start a pattern in any of the three libraries. + +26. Give configure error if --enable-cpp but no C++ compiler found. + + +Version 8.31 06-July-2012 +------------------------- + +1. Fixing a wrong JIT test case and some compiler warnings. + +2. Removed a bashism from the RunTest script. + +3. Add a cast to pcre_exec.c to fix the warning "unary minus operator applied + to unsigned type, result still unsigned" that was given by an MS compiler + on encountering the code "-sizeof(xxx)". + +4. Partial matching support is added to the JIT compiler. + +5. Fixed several bugs concerned with partial matching of items that consist + of more than one character: + + (a) /^(..)\1/ did not partially match "aba" because checking references was + done on an "all or nothing" basis. This also applied to repeated + references. + + (b) \R did not give a hard partial match if \r was found at the end of the + subject. + + (c) \X did not give a hard partial match after matching one or more + characters at the end of the subject. + + (d) When newline was set to CRLF, a pattern such as /a$/ did not recognize + a partial match for the string "\r". + + (e) When newline was set to CRLF, the metacharacter "." did not recognize + a partial match for a CR character at the end of the subject string. + +6. If JIT is requested using /S++ or -s++ (instead of just /S+ or -s+) when + running pcretest, the text "(JIT)" added to the output whenever JIT is + actually used to run the match. + +7. Individual JIT compile options can be set in pcretest by following -s+[+] + or /S+[+] with a digit between 1 and 7. + +8. OP_NOT now supports any UTF character not just single-byte ones. + +9. (*MARK) control verb is now supported by the JIT compiler. + +10. The command "./RunTest list" lists the available tests without actually + running any of them. (Because I keep forgetting what they all are.) + +11. Add PCRE_INFO_MAXLOOKBEHIND. + +12. Applied a (slightly modified) user-supplied patch that improves performance + when the heap is used for recursion (compiled with --disable-stack-for- + recursion). Instead of malloc and free for each heap frame each time a + logical recursion happens, frames are retained on a chain and re-used where + possible. This sometimes gives as much as 30% improvement. + +13. As documented, (*COMMIT) is now confined to within a recursive subpattern + call. + +14. As documented, (*COMMIT) is now confined to within a positive assertion. + +15. It is now possible to link pcretest with libedit as an alternative to + libreadline. + +16. (*COMMIT) control verb is now supported by the JIT compiler. + +17. The Unicode data tables have been updated to Unicode 6.1.0. + +18. Added --file-list option to pcregrep. + +19. Added binary file support to pcregrep, including the -a, --binary-files, + -I, and --text options. + +20. The madvise function is renamed for posix_madvise for QNX compatibility + reasons. Fixed by Giuseppe D'Angelo. + +21. Fixed a bug for backward assertions with REVERSE 0 in the JIT compiler. + +22. Changed the option for creating symbolic links for 16-bit man pages from + -s to -sf so that re-installing does not cause issues. + +23. Support PCRE_NO_START_OPTIMIZE in JIT as (*MARK) support requires it. + +24. Fixed a very old bug in pcretest that caused errors with restarted DFA + matches in certain environments (the workspace was not being correctly + retained). Also added to pcre_dfa_exec() a simple plausibility check on + some of the workspace data at the beginning of a restart. + +25. \s*\R was auto-possessifying the \s* when it should not, whereas \S*\R + was not doing so when it should - probably a typo introduced by SVN 528 + (change 8.10/14). + +26. When PCRE_UCP was not set, \w+\x{c4} was incorrectly auto-possessifying the + \w+ when the character tables indicated that \x{c4} was a word character. + There were several related cases, all because the tests for doing a table + lookup were testing for characters less than 127 instead of 255. + +27. If a pattern contains capturing parentheses that are not used in a match, + their slots in the ovector are set to -1. For those that are higher than + any matched groups, this happens at the end of processing. In the case when + there were back references that the ovector was too small to contain + (causing temporary malloc'd memory to be used during matching), and the + highest capturing number was not used, memory off the end of the ovector + was incorrectly being set to -1. (It was using the size of the temporary + memory instead of the true size.) + +28. To catch bugs like 27 using valgrind, when pcretest is asked to specify an + ovector size, it uses memory at the end of the block that it has got. + +29. Check for an overlong MARK name and give an error at compile time. The + limit is 255 for the 8-bit library and 65535 for the 16-bit library. + +30. JIT compiler update. + +31. JIT is now supported on jailbroken iOS devices. Thanks for Ruiger + Rill for the patch. + +32. Put spaces around SLJIT_PRINT_D in the JIT compiler. Required by CXX11. + +33. Variable renamings in the PCRE-JIT compiler. No functionality change. + +34. Fixed typos in pcregrep: in two places there was SUPPORT_LIBZ2 instead of + SUPPORT_LIBBZ2. This caused a build problem when bzip2 but not gzip (zlib) + was enabled. + +35. Improve JIT code generation for greedy plus quantifier. + +36. When /((?:a?)*)*c/ or /((?>a?)*)*c/ was matched against "aac", it set group + 1 to "aa" instead of to an empty string. The bug affected repeated groups + that could potentially match an empty string. + +37. Optimizing single character iterators in JIT. + +38. Wide characters specified with \uxxxx in JavaScript mode are now subject to + the same checks as \x{...} characters in non-JavaScript mode. Specifically, + codepoints that are too big for the mode are faulted, and in a UTF mode, + disallowed codepoints are also faulted. + +39. If PCRE was compiled with UTF support, in three places in the DFA + matcher there was code that should only have been obeyed in UTF mode, but + was being obeyed unconditionally. In 8-bit mode this could cause incorrect + processing when bytes with values greater than 127 were present. In 16-bit + mode the bug would be provoked by values in the range 0xfc00 to 0xdc00. In + both cases the values are those that cannot be the first data item in a UTF + character. The three items that might have provoked this were recursions, + possessively repeated groups, and atomic groups. + +40. Ensure that libpcre is explicitly listed in the link commands for pcretest + and pcregrep, because some OS require shared objects to be explicitly + passed to ld, causing the link step to fail if they are not. + +41. There were two incorrect #ifdefs in pcre_study.c, meaning that, in 16-bit + mode, patterns that started with \h* or \R* might be incorrectly matched. + + +Version 8.30 04-February-2012 +----------------------------- + +1. Renamed "isnumber" as "is_a_number" because in some Mac environments this + name is defined in ctype.h. + +2. Fixed a bug in fixed-length calculation for lookbehinds that would show up + only in quite long subpatterns. + +3. Removed the function pcre_info(), which has been obsolete and deprecated + since it was replaced by pcre_fullinfo() in February 2000. + +4. For a non-anchored pattern, if (*SKIP) was given with a name that did not + match a (*MARK), and the match failed at the start of the subject, a + reference to memory before the start of the subject could occur. This bug + was introduced by fix 17 of release 8.21. + +5. A reference to an unset group with zero minimum repetition was giving + totally wrong answers (in non-JavaScript-compatibility mode). For example, + /(another)?(\1?)test/ matched against "hello world test". This bug was + introduced in release 8.13. + +6. Add support for 16-bit character strings (a large amount of work involving + many changes and refactorings). + +7. RunGrepTest failed on msys because \r\n was replaced by whitespace when the + command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken + from a file. + +8. Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size + rounding is not applied in this particular case). + +9. The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected + if they appear, or are escaped, in patterns. + +10. Get rid of a number of -Wunused-but-set-variable warnings. + +11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark + "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all. + Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern + also returns the mark "x". This bug applied to capturing parentheses, + non-capturing parentheses, and atomic parentheses. It also applied to some + assertions. + +12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version + information out of configure.ac instead of relying on pcre.h.generic, which + is not stored in the repository. + +13. Applied Dmitry V. Levin's patch for a more portable method for linking with + -lreadline. + +14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C. + +15. Applied Graycode's patch to put the top-level frame on the stack rather + than the heap when not using the stack for recursion. This gives a + performance improvement in many cases when recursion is not deep. + +16. Experimental code added to "pcretest -C" to output the stack frame size. + + +Version 8.21 12-Dec-2011 +------------------------ + +1. Updating the JIT compiler. + +2. JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases + are added as well. + +3. Fix cache-flush issue on PowerPC (It is still an experimental JIT port). + PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before + calling _pcre_jit_exec. Some extra comments are added. + +4. (*MARK) settings inside atomic groups that do not contain any capturing + parentheses, for example, (?>a(*:m)), were not being passed out. This bug + was introduced by change 18 for 8.20. + +5. Supporting of \x, \U and \u in JavaScript compatibility mode based on the + ECMA-262 standard. + +6. Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were + erroneously being rejected as "not fixed length" if PCRE_CASELESS was set. + This bug was probably introduced by change 9 of 8.13. + +7. While fixing 6 above, I noticed that a number of other items were being + incorrectly rejected as "not fixed length". This arose partly because newer + opcodes had not been added to the fixed-length checking code. I have (a) + corrected the bug and added tests for these items, and (b) arranged for an + error to occur if an unknown opcode is encountered while checking for fixed + length instead of just assuming "not fixed length". The items that were + rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP), + (*THEN), \h, \H, \v, \V, and single character negative classes with fixed + repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS. + +8. A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was + being incorrectly compiled and would have given unpredicatble results. + +9. A possessively repeated subpattern with minimum repeat count greater than + one behaved incorrectly. For example, (A){2,}+ behaved as if it was + (A)(A)++ which meant that, after a subsequent mismatch, backtracking into + the first (A) could occur when it should not. + +10. Add a cast and remove a redundant test from the code. + +11. JIT should use pcre_malloc/pcre_free for allocation. + +12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems + best practice nowadays, and helps with cross-compiling. (If the exec_prefix + is anything other than /usr, -L is still shown). + +13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching. + +14. Perl does not support \N without a following name in a [] class; PCRE now + also gives an error. + +15. If a forward reference was repeated with an upper limit of around 2000, + it caused the error "internal error: overran compiling workspace". The + maximum number of forward references (including repeats) was limited by the + internal workspace, and dependent on the LINK_SIZE. The code has been + rewritten so that the workspace expands (via pcre_malloc) if necessary, and + the default depends on LINK_SIZE. There is a new upper limit (for safety) + of around 200,000 forward references. While doing this, I also speeded up + the filling in of repeated forward references. + +16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was + incorrectly expecting the subject to contain another "a" after the start. + +17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier + in the match, the SKIP should be ignored. This was not happening; instead + the SKIP was being treated as NOMATCH. For patterns such as + /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never + tested. + +18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is + now much more compatible with Perl, in particular in cases where the result + is a non-match for a non-anchored pattern. For example, if + /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name + "m", where previously it did not return a name. A side effect of this + change is that for partial matches, the last encountered mark name is + returned, as for non matches. A number of tests that were previously not + Perl-compatible have been moved into the Perl-compatible test files. The + refactoring has had the pleasing side effect of removing one argument from + the match() function, thus reducing its stack requirements. + +19. If the /S+ option was used in pcretest to study a pattern using JIT, + subsequent uses of /S (without +) incorrectly behaved like /S+. + +21. Retrieve executable code size support for the JIT compiler and fixing + some warnings. + +22. A caseless match of a UTF-8 character whose other case uses fewer bytes did + not work when the shorter character appeared right at the end of the + subject string. + +23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit + systems. + +24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also + output it when the /M option is used in pcretest. + +25. The CheckMan script was not being included in the distribution. Also, added + an explicit "perl" to run Perl scripts from the PrepareRelease script + because this is reportedly needed in Windows. + +26. If study data was being save in a file and studying had not found a set of + "starts with" bytes for the pattern, the data written to the file (though + never used) was taken from uninitialized memory and so caused valgrind to + complain. + +27. Updated RunTest.bat as provided by Sheri Pierce. + +28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c. + +29. Computation of memory usage for the table of capturing group names was + giving an unnecessarily large value. + + +Version 8.20 21-Oct-2011 +------------------------ + +1. Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had + a POSIX class. After further experiments with Perl, which convinced me that + Perl has bugs and confusions, a closing square bracket is no longer allowed + in a POSIX name. This bug also affected patterns with classes that started + with full stops. + +2. If a pattern such as /(a)b|ac/ is matched against "ac", there is no + captured substring, but while checking the failing first alternative, + substring 1 is temporarily captured. If the output vector supplied to + pcre_exec() was not big enough for this capture, the yield of the function + was still zero ("insufficient space for captured substrings"). This cannot + be totally fixed without adding another stack variable, which seems a lot + of expense for a edge case. However, I have improved the situation in cases + such as /(a)(b)x|abc/ matched against "abc", where the return code + indicates that fewer than the maximum number of slots in the ovector have + been set. + +3. Related to (2) above: when there are more back references in a pattern than + slots in the output vector, pcre_exec() uses temporary memory during + matching, and copies in the captures as far as possible afterwards. It was + using the entire output vector, but this conflicts with the specification + that only 2/3 is used for passing back captured substrings. Now it uses + only the first 2/3, for compatibility. This is, of course, another edge + case. + +4. Zoltan Herczeg's just-in-time compiler support has been integrated into the + main code base, and can be used by building with --enable-jit. When this is + done, pcregrep automatically uses it unless --disable-pcregrep-jit or the + runtime --no-jit option is given. + +5. When the number of matches in a pcre_dfa_exec() run exactly filled the + ovector, the return from the function was zero, implying that there were + other matches that did not fit. The correct "exactly full" value is now + returned. + +6. If a subpattern that was called recursively or as a subroutine contained + (*PRUNE) or any other control that caused it to give a non-standard return, + invalid errors such as "Error -26 (nested recursion at the same subject + position)" or even infinite loops could occur. + +7. If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped + computing the minimum length on reaching *ACCEPT, and so ended up with the + wrong value of 1 rather than 0. Further investigation indicates that + computing a minimum subject length in the presence of *ACCEPT is difficult + (think back references, subroutine calls), and so I have changed the code + so that no minimum is registered for a pattern that contains *ACCEPT. + +8. If (*THEN) was present in the first (true) branch of a conditional group, + it was not handled as intended. [But see 16 below.] + +9. Replaced RunTest.bat and CMakeLists.txt with improved versions provided by + Sheri Pierce. + +10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that + the first byte in a match must be "a". + +11. Change 17 for 8.13 increased the recursion depth for patterns like + /a(?:.)*?a/ drastically. I've improved things by remembering whether a + pattern contains any instances of (*THEN). If it does not, the old + optimizations are restored. It would be nice to do this on a per-group + basis, but at the moment that is not feasible. + +12. In some environments, the output of pcretest -C is CRLF terminated. This + broke RunTest's code that checks for the link size. A single white space + character after the value is now allowed for. + +13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french". + For "fr", it uses the Windows-specific input and output files. + +14. If (*THEN) appeared in a group that was called recursively or as a + subroutine, it did not work as intended. [But see next item.] + +15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex + pattern fragments (but not containing any | characters). If A and B are + matched, but there is a failure in C so that it backtracks to (*THEN), PCRE + was behaving differently to Perl. PCRE backtracked into A, but Perl goes to + D. In other words, Perl considers parentheses that do not contain any | + characters to be part of a surrounding alternative, whereas PCRE was + treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles + differently. PCRE now behaves in the same way as Perl, except in the case + of subroutine/recursion calls such as (?1) which have in any case always + been different (but PCRE had them first :-). + +16. Related to 15 above: Perl does not treat the | in a conditional group as + creating alternatives. Such a group is treated in the same way as an + ordinary group without any | characters when processing (*THEN). PCRE has + been changed to match Perl's behaviour. + +17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the + RunGrepTest script failed. + +18. Change 22 for version 13 caused atomic groups to use more stack. This is + inevitable for groups that contain captures, but it can lead to a lot of + stack use in large patterns. The old behaviour has been restored for atomic + groups that do not contain any capturing parentheses. + +19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not + suppress the check for a minimum subject length at run time. (If it was + given to pcre_exec() or pcre_dfa_exec() it did work.) + +20. Fixed an ASCII-dependent infelicity in pcretest that would have made it + fail to work when decoding hex characters in data strings in EBCDIC + environments. + +21. It appears that in at least one Mac OS environment, the isxdigit() function + is implemented as a macro that evaluates to its argument more than once, + contravening the C 90 Standard (I haven't checked a later standard). There + was an instance in pcretest which caused it to go wrong when processing + \x{...} escapes in subject strings. The has been rewritten to avoid using + things like p++ in the argument of isxdigit(). + + +Version 8.13 16-Aug-2011 +------------------------ + +1. The Unicode data tables have been updated to Unicode 6.0.0. + +2. Two minor typos in pcre_internal.h have been fixed. + +3. Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and + pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr() + in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2). + +4. There were a number of related bugs in the code for matching backrefences + caselessly in UTF-8 mode when codes for the characters concerned were + different numbers of bytes. For example, U+023A and U+2C65 are an upper + and lower case pair, using 2 and 3 bytes, respectively. The main bugs were: + (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte + code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a + 2-byte code at the end of the subject (it thought there wasn't enough data + left). + +5. Comprehensive information about what went wrong is now returned by + pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long + as the output vector has at least 2 elements. The offset of the start of + the failing character and a reason code are placed in the vector. + +6. When the UTF-8 string check fails for pcre_compile(), the offset that is + now returned is for the first byte of the failing character, instead of the + last byte inspected. This is an incompatible change, but I hope it is small + enough not to be a problem. It makes the returned offset consistent with + pcre_exec() and pcre_dfa_exec(). + +7. pcretest now gives a text phrase as well as the error number when + pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check + failure, the offset and reason code are output. + +8. When \R was used with a maximizing quantifier it failed to skip backwards + over a \r\n pair if the subsequent match failed. Instead, it just skipped + back over a single character (\n). This seems wrong (because it treated the + two characters as a single entity when going forwards), conflicts with the + documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the + behaviour of \R* different to (\R)*, which also seems wrong. The behaviour + has been changed. + +9. Some internal refactoring has changed the processing so that the handling + of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile + time (the PCRE_DOTALL option was changed this way some time ago: version + 7.7 change 16). This has made it possible to abolish the OP_OPT op code, + which was always a bit of a fudge. It also means that there is one less + argument for the match() function, which reduces its stack requirements + slightly. This change also fixes an incompatibility with Perl: the pattern + (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match. + +10. More internal refactoring has drastically reduced the number of recursive + calls to match() for possessively repeated groups such as (abc)++ when + using pcre_exec(). + +11. While implementing 10, a number of bugs in the handling of groups were + discovered and fixed: + + (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind). + (a|)*(?1) gave a compile-time internal error. + ((a|)+)+ did not notice that the outer group could match an empty string. + (^a|^)+ was not marked as anchored. + (.*a|.*)+ was not marked as matching at start or after a newline. + +12. Yet more internal refactoring has removed another argument from the match() + function. Special calls to this function are now indicated by setting a + value in a variable in the "match data" data block. + +13. Be more explicit in pcre_study() instead of relying on "default" for + opcodes that mean there is no starting character; this means that when new + ones are added and accidentally left out of pcre_study(), testing should + pick them up. + +14. The -s option of pcretest has been documented for ages as being an old + synonym of -m (show memory usage). I have changed it to mean "force study + for every regex", that is, assume /S for every regex. This is similar to -i + and -d etc. It's slightly incompatible, but I'm hoping nobody is still + using it. It makes it easier to run collections of tests with and without + study enabled, and thereby test pcre_study() more easily. All the standard + tests are now run with and without -s (but some patterns can be marked as + "never study" - see 20 below). + +15. When (*ACCEPT) was used in a subpattern that was called recursively, the + restoration of the capturing data to the outer values was not happening + correctly. + +16. If a recursively called subpattern ended with (*ACCEPT) and matched an + empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole + pattern had matched an empty string, and so incorrectly returned a no + match. + +17. There was optimizing code for the last branch of non-capturing parentheses, + and also for the obeyed branch of a conditional subexpression, which used + tail recursion to cut down on stack usage. Unfortunately, now that there is + the possibility of (*THEN) occurring in these branches, tail recursion is + no longer possible because the return has to be checked for (*THEN). These + two optimizations have therefore been removed. [But see 8.20/11 above.] + +18. If a pattern containing \R was studied, it was assumed that \R always + matched two bytes, thus causing the minimum subject length to be + incorrectly computed because \R can also match just one byte. + +19. If a pattern containing (*ACCEPT) was studied, the minimum subject length + was incorrectly computed. + +20. If /S is present twice on a test pattern in pcretest input, it now + *disables* studying, thereby overriding the use of -s on the command line + (see 14 above). This is necessary for one or two tests to keep the output + identical in both cases. + +21. When (*ACCEPT) was used in an assertion that matched an empty string and + PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion. + +22. When an atomic group that contained a capturing parenthesis was + successfully matched, but the branch in which it appeared failed, the + capturing was not being forgotten if a higher numbered group was later + captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing + group 1 to "a", when in fact it should be unset. This applied to multi- + branched capturing and non-capturing groups, repeated or not, and also to + positive assertions (capturing in negative assertions does not happen + in PCRE) and also to nested atomic groups. + +23. Add the ++ qualifier feature to pcretest, to show the remainder of the + subject after a captured substring, to make it easier to tell which of a + number of identical substrings has been captured. + +24. The way atomic groups are processed by pcre_exec() has been changed so that + if they are repeated, backtracking one repetition now resets captured + values correctly. For example, if ((?>(a+)b)+aabab) is matched against + "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as + "aaa". Previously, it would have been "a". As part of this code + refactoring, the way recursive calls are handled has also been changed. + +25. If an assertion condition captured any substrings, they were not passed + back unless some other capturing happened later. For example, if + (?(?=(a))a) was matched against "a", no capturing was returned. + +26. When studying a pattern that contained subroutine calls or assertions, + the code for finding the minimum length of a possible match was handling + direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where + group 1 called group 2 while simultaneously a separate group 2 called group + 1). A stack overflow occurred in this case. I have fixed this by limiting + the recursion depth to 10. + +27. Updated RunTest.bat in the distribution to the version supplied by Tom + Fortmann. This supports explicit test numbers on the command line, and has + argument validation and error reporting. + +28. An instance of \X with an unlimited repeat could fail if at any point the + first character it looked at was a mark character. + +29. Some minor code refactoring concerning Unicode properties and scripts + should reduce the stack requirement of match() slightly. + +30. Added the '=' option to pcretest to check the setting of unused capturing + slots at the end of the pattern, which are documented as being -1, but are + not included in the return count. + +31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE + compiled something random. Now it gives a compile-time error (as does + Perl). + +32. A *MARK encountered during the processing of a positive assertion is now + recorded and passed back (compatible with Perl). + +33. If --only-matching or --colour was set on a pcregrep call whose pattern + had alternative anchored branches, the search for a second match in a line + was done as if at the line start. Thus, for example, /^01|^02/ incorrectly + matched the line "0102" twice. The same bug affected patterns that started + with a backwards assertion. For example /\b01|\b02/ also matched "0102" + twice. + +34. Previously, PCRE did not allow quantification of assertions. However, Perl + does, and because of capturing effects, quantifying parenthesized + assertions may at times be useful. Quantifiers are now allowed for + parenthesized assertions. + +35. A minor code tidy in pcre_compile() when checking options for \R usage. + +36. \g was being checked for fancy things in a character class, when it should + just be a literal "g". + +37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the + appearance of a nested POSIX class supersedes an apparent external class. + For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also, + unescaped square brackets may also appear as part of class names. For + example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves + more like Perl. (But see 8.20/1 above.) + +38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this + was because it thought it was \N{name}, which is not supported). + +39. Add minix to OS list not supporting the -S option in pcretest. + +40. PCRE tries to detect cases of infinite recursion at compile time, but it + cannot analyze patterns in sufficient detail to catch mutual recursions + such as ((?1))((?2)). There is now a runtime test that gives an error if a + subgroup is called recursively as a subpattern for a second time at the + same position in the subject string. In previous releases this might have + been caught by the recursion limit, or it might have run out of stack. + +41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can + happen only once. PCRE was, however incorrectly giving a compile time error + "recursive call could loop indefinitely" because it cannot analyze the + pattern in sufficient detail. The compile time test no longer happens when + PCRE is compiling a conditional subpattern, but actual runaway loops are + now caught at runtime (see 40 above). + +42. It seems that Perl allows any characters other than a closing parenthesis + to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE + has been changed to be the same. + +43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so + as not to get warnings when autogen.sh is called. Also changed + AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro). + +44. To help people who use pcregrep to scan files containing exceedingly long + lines, the following changes have been made: + + (a) The default value of the buffer size parameter has been increased from + 8K to 20K. (The actual buffer used is three times this size.) + + (b) The default can be changed by ./configure --with-pcregrep-bufsize when + PCRE is built. + + (c) A --buffer-size=n option has been added to pcregrep, to allow the size + to be set at run time. + + (d) Numerical values in pcregrep options can be followed by K or M, for + example --buffer-size=50K. + + (e) If a line being scanned overflows pcregrep's buffer, an error is now + given and the return code is set to 2. + +45. Add a pointer to the latest mark to the callout data block. + +46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a + partial match of an empty string instead of no match. This was specific to + the use of ".". + +47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a + complete match instead of a partial match. This bug was dependent on both + the PCRE_UTF8 and PCRE_DOTALL options being set. + +48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the + starting byte set, because \b was not being ignored. + + +Version 8.12 15-Jan-2011 +------------------------ + +1. Fixed some typos in the markup of the man pages, and wrote a script that + checks for such things as part of the documentation building process. + +2. On a big-endian 64-bit system, pcregrep did not correctly process the + --match-limit and --recursion-limit options (added for 8.11). In + particular, this made one of the standard tests fail. (The integer value + went into the wrong half of a long int.) + +3. If the --colour option was given to pcregrep with -v (invert match), it + did strange things, either producing crazy output, or crashing. It should, + of course, ignore a request for colour when reporting lines that do not + match. + +4. Another pcregrep bug caused similar problems if --colour was specified with + -M (multiline) and the pattern match finished with a line ending. + +5. In pcregrep, when a pattern that ended with a literal newline sequence was + matched in multiline mode, the following line was shown as part of the + match. This seems wrong, so I have changed it. + +6. Another pcregrep bug in multiline mode, when --colour was specified, caused + the check for further matches in the same line (so they could be coloured) + to overrun the end of the current line. If another match was found, it was + incorrectly shown (and then shown again when found in the next line). + +7. If pcregrep was compiled under Windows, there was a reference to the + function pcregrep_exit() before it was defined. I am assuming this was + the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was + reported by a user. I've moved the definition above the reference. + + +Version 8.11 10-Dec-2010 +------------------------ + +1. (*THEN) was not working properly if there were untried alternatives prior + to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it + backtracked to try for "b" instead of moving to the next alternative branch + at the same level (in this case, to look for "c"). The Perl documentation + is clear that when (*THEN) is backtracked onto, it goes to the "next + alternative in the innermost enclosing group". + +2. (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern + such as (A(*COMMIT)B(*THEN)C|D) any failure after matching A should + result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and + (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides + (*THEN). + +3. If \s appeared in a character class, it removed the VT character from + the class, even if it had been included by some previous item, for example + in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part + of \s, but is part of the POSIX "space" class.) + +4. A partial match never returns an empty string (because you can always + match an empty string at the end of the subject); however the checking for + an empty string was starting at the "start of match" point. This has been + changed to the "earliest inspected character" point, because the returned + data for a partial match starts at this character. This means that, for + example, /(?<=abc)def/ gives a partial match for the subject "abc" + (previously it gave "no match"). + +5. Changes have been made to the way PCRE_PARTIAL_HARD affects the matching + of $, \z, \Z, \b, and \B. If the match point is at the end of the string, + previously a full match would be given. However, setting PCRE_PARTIAL_HARD + has an implication that the given string is incomplete (because a partial + match is preferred over a full match). For this reason, these items now + give a partial match in this situation. [Aside: previously, the one case + /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial + match rather than a full match, which was wrong by the old rules, but is + now correct.] + +6. There was a bug in the handling of #-introduced comments, recognized when + PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set. + If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose + UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when + scanning for the end of the comment. (*Character* 0x85 is an "any" newline, + but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several + places in pcre_compile(). + +7. Related to (6) above, when pcre_compile() was skipping #-introduced + comments when looking ahead for named forward references to subpatterns, + the only newline sequence it recognized was NL. It now handles newlines + according to the set newline convention. + +8. SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the + former, but used strtoul(), whereas pcretest avoided strtoul() but did not + cater for a lack of strerror(). These oversights have been fixed. + +9. Added --match-limit and --recursion-limit to pcregrep. + +10. Added two casts needed to build with Visual Studio when NO_RECURSE is set. + +11. When the -o option was used, pcregrep was setting a return code of 1, even + when matches were found, and --line-buffered was not being honoured. + +12. Added an optional parentheses number to the -o and --only-matching options + of pcregrep. + +13. Imitating Perl's /g action for multiple matches is tricky when the pattern + can match an empty string. The code to do it in pcretest and pcredemo + needed fixing: + + (a) When the newline convention was "crlf", pcretest got it wrong, skipping + only one byte after an empty string match just before CRLF (this case + just got forgotten; "any" and "anycrlf" were OK). + + (b) The pcretest code also had a bug, causing it to loop forever in UTF-8 + mode when an empty string match preceded an ASCII character followed by + a non-ASCII character. (The code for advancing by one character rather + than one byte was nonsense.) + + (c) The pcredemo.c sample program did not have any code at all to handle + the cases when CRLF is a valid newline sequence. + +14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given + as a starting offset was within the subject string. There is now a new + error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is + negative or greater than the length of the string. In order to test this, + pcretest is extended to allow the setting of negative starting offsets. + +15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the + starting offset points to the beginning of a UTF-8 character was + unnecessarily clumsy. I tidied it up. + +16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a + bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD. + +17. Nobody had reported that the --include_dir option, which was added in + release 7.7 should have been called --include-dir (hyphen, not underscore) + for compatibility with GNU grep. I have changed it to --include-dir, but + left --include_dir as an undocumented synonym, and the same for + --exclude-dir, though that is not available in GNU grep, at least as of + release 2.5.4. + +18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8 + characters from a string of bytes) have been redefined so as not to use + loops, in order to improve performance in some environments. At the same + time, I abstracted some of the common code into auxiliary macros to save + repetition (this should not affect the compiled code). + +19. If \c was followed by a multibyte UTF-8 character, bad things happened. A + compile-time error is now given if \c is not followed by an ASCII + character, that is, a byte less than 128. (In EBCDIC mode, the code is + different, and any byte value is allowed.) + +20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_ + START_OPTIMIZE option, which is now allowed at compile time - but just + passed through to pcre_exec() or pcre_dfa_exec(). This makes it available + to pcregrep and other applications that have no direct access to PCRE + options. The new /Y option in pcretest sets this option when calling + pcre_compile(). + +21. Change 18 of release 8.01 broke the use of named subpatterns for recursive + back references. Groups containing recursive back references were forced to + be atomic by that change, but in the case of named groups, the amount of + memory required was incorrectly computed, leading to "Failed: internal + error: code overflow". This has been fixed. + +22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and + pcretest.c, to avoid build problems in some Borland environments. + + +Version 8.10 25-Jun-2010 +------------------------ + +1. Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and + THEN. + +2. (*ACCEPT) was not working when inside an atomic group. + +3. Inside a character class, \B is treated as a literal by default, but + faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option + causes the error). The code is unchanged, but I tidied the documentation. + +4. Inside a character class, PCRE always treated \R and \X as literals, + whereas Perl faults them if its -w option is set. I have changed PCRE so + that it faults them when PCRE_EXTRA is set. + +5. Added support for \N, which always matches any character other than + newline. (It is the same as "." when PCRE_DOTALL is not set.) + +6. When compiling pcregrep with newer versions of gcc which may have + FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite', + declared with attribute warn_unused_result" were given. Just casting the + result to (void) does not stop the warnings; a more elaborate fudge is + needed. I've used a macro to implement this. + +7. Minor change to pcretest.c to avoid a compiler warning. + +8. Added four artifical Unicode properties to help with an option to make + \s etc use properties (see next item). The new properties are: Xan + (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word). + +9. Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes + use Unicode properties. (*UCP) at the start of a pattern can be used to set + this option. Modified pcretest to add /W to test this facility. Added + REG_UCP to make it available via the POSIX interface. + +10. Added --line-buffered to pcregrep. + +11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was + studied, and the match started with a letter with a code point greater than + 127 whose first byte was different to the first byte of the other case of + the letter, the other case of this starting letter was not recognized + (#976). + +12. If a pattern that was studied started with a repeated Unicode property + test, for example, \p{Nd}+, there was the theoretical possibility of + setting up an incorrect bitmap of starting bytes, but fortunately it could + not have actually happened in practice until change 8 above was made (it + added property types that matched character-matching opcodes). + +13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of + possible starting bytes for non-anchored patterns. + +14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes + \R, and also a number of cases that involve Unicode properties, both + explicit and implicit when PCRE_UCP is set. + +15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8 + input, it could crash or give wrong results if characters with values + greater than 0xc0 were present in the subject string. (Detail: it assumed + UTF-8 input when processing these items.) + +16. Added a lot of (int) casts to avoid compiler warnings in systems where + size_t is 64-bit (#991). + +17. Added a check for running out of memory when PCRE is compiled with + --disable-stack-for-recursion (#990). + +18. If the last data line in a file for pcretest does not have a newline on + the end, a newline was missing in the output. + +19. The default pcre_chartables.c file recognizes only ASCII characters (values + less than 128) in its various bitmaps. However, there is a facility for + generating tables according to the current locale when PCRE is compiled. It + turns out that in some environments, 0x85 and 0xa0, which are Unicode space + characters, are recognized by isspace() and therefore were getting set in + these tables, and indeed these tables seem to approximate to ISO 8859. This + caused a problem in UTF-8 mode when pcre_study() was used to create a list + of bytes that can start a match. For \s, it was including 0x85 and 0xa0, + which of course cannot start UTF-8 characters. I have changed the code so + that only real ASCII characters (less than 128) and the correct starting + bytes for UTF-8 encodings are set for characters greater than 127 when in + UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different + altogether.) + +20. Added the /T option to pcretest so as to be able to run tests with non- + standard character tables, thus making it possible to include the tests + used for 19 above in the standard set of tests. + +21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward + reference to a subpattern the other side of a comment that contains an + opening parenthesis caused either an internal compiling error, or a + reference to the wrong subpattern. + + +Version 8.02 19-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. + +5. A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive + quantifier applied to a forward-referencing subroutine call, could compile + incorrect code or give the error "internal error: previously-checked + referenced subpattern not found". + +6. Both MS Visual Studio and Symbian OS have problems with initializing + variables to point to external functions. For these systems, therefore, + pcre_malloc etc. are now initialized to local functions that call the + relevant global functions. + +7. There were two entries missing in the vectors called coptable and poptable + in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors. + I've fixed the data, and added a kludgy way of testing at compile time that + the lengths are correct (equal to the number of opcodes). + +8. Following on from 7, I added a similar kludge to check the length of the + eint vector in pcreposix.c. + +9. Error texts for pcre_compile() are held as one long string to avoid too + much relocation at load time. To find a text, the string is searched, + counting zeros. There was no check for running off the end of the string, + which could happen if a new error number was added without updating the + string. + +10. \K gave a compile-time error if it appeared in a lookbehind assersion. + +11. \K was not working if it appeared in an atomic group or in a group that + was called as a "subroutine", or in an assertion. Perl 5.11 documents that + \K is "not well defined" if used in an assertion. PCRE now accepts it if + the assertion is positive, but not if it is negative. + +12. Change 11 fortuitously reduced the size of the stack frame used in the + "match()" function of pcre_exec.c by one pointer. Forthcoming + implementation of support for (*MARK) will need an extra pointer on the + stack; I have reserved it now, so that the stack frame size does not + decrease. + +13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other + item in branch that calls a recursion is a subroutine call - as in the + second branch in the above example - was incorrectly given the compile- + time error "recursive call could loop indefinitely" because pcre_compile() + was not correctly checking the subroutine for matching a non-empty string. + +14. The checks for overrunning compiling workspace could trigger after an + overrun had occurred. This is a "should never occur" error, but it can be + triggered by pathological patterns such as hundreds of nested parentheses. + The checks now trigger 100 bytes before the end of the workspace. + +15. Fix typo in configure.ac: "srtoq" should be "strtoq". + + +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 + 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. + +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 + 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 + recognized by pcregrep, which required --regex pattern or --regexp pattern + (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 + 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 + 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])(?<A>))/. + [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 +--------------------- + +1. When building with support for bzlib/zlib (pcregrep) and/or readline + (pcretest), all targets were linked against these libraries. This included + libpcre, libpcreposix, and libpcrecpp, even though they do not use these + libraries. This caused unwanted dependencies to be created. This problem + has been fixed, and now only pcregrep is linked with bzlib/zlib and only + pcretest is linked with readline. + +2. The "typedef int BOOL" in pcre_internal.h that was included inside the + "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been + moved outside it again, because FALSE and TRUE are already defined in AIX, + but BOOL is not. + +3. The pcre_config() function was treating the PCRE_MATCH_LIMIT and + PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints. + +4. The pcregrep documentation said spaces were inserted as well as colons (or + hyphens) following file names and line numbers when outputting matching + lines. This is not true; no spaces are inserted. I have also clarified the + wording for the --colour (or --color) option. + +5. In pcregrep, when --colour was used with -o, the list of matching strings + was not coloured; this is different to GNU grep, so I have changed it to be + the same. + +6. When --colo(u)r was used in pcregrep, only the first matching substring in + each matching line was coloured. Now it goes on to look for further matches + of any of the test patterns, which is the same behaviour as GNU grep. + +7. A pattern that could match an empty string could cause pcregrep to loop; it + doesn't make sense to accept an empty string match in pcregrep, so I have + locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this + seems to be how GNU grep behaves. [But see later change 40 for release + 8.33.] + +8. The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at + start or after a newline", because the conditional assertion was not being + correctly handled. The rule now is that both the assertion and what follows + in the first alternative must satisfy the test. + +9. If auto-callout was enabled in a pattern with a conditional group whose + condition was an assertion, PCRE could crash during matching, both with + pcre_exec() and pcre_dfa_exec(). + +10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was + used for matching. + +11. Unicode property support in character classes was not working for + characters (bytes) greater than 127 when not in UTF-8 mode. + +12. Added the -M command line option to pcretest. + +14. Added the non-standard REG_NOTEMPTY option to the POSIX interface. + +15. Added the PCRE_NO_START_OPTIMIZE match-time option. + +16. Added comments and documentation about mis-use of no_arg in the C++ + wrapper. + +17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch + from Martin Jerabek that uses macro names for all relevant character and + string constants. + +18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and + SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without + SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of + these, but not everybody uses configure. + +19. A conditional group that had only one branch was not being correctly + recognized as an item that could match an empty string. This meant that an + enclosing group might also not be so recognized, causing infinite looping + (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$ + with the subject "ab", where knowledge that the repeated group can match + nothing is needed in order to break the loop. + +20. If a pattern that was compiled with callouts was matched using pcre_dfa_ + exec(), but without supplying a callout function, matching went wrong. + +21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory + leak if the size of the offset vector was greater than 30. When the vector + is smaller, the saved offsets during recursion go onto a local stack + vector, but for larger vectors malloc() is used. It was failing to free + when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal" + error, in fact). + +22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the + heapframe that is used only when UTF-8 support is enabled. This caused no + problem, but was untidy. + +23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name + CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is + included within another project. + +24. Steven Van Ingelgem's patches to add more options to the CMake support, + slightly modified by me: + + (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including + not building pcregrep. + + (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only + if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep. + +25. Forward references, both numeric and by name, in patterns that made use of + duplicate group numbers, could behave incorrectly or give incorrect errors, + because when scanning forward to find the reference group, PCRE was not + taking into account the duplicate group numbers. A pattern such as + ^X(?3)(a)(?|(b)|(q))(Y) is an example. + +26. Changed a few more instances of "const unsigned char *" to USPTR, making + the feature of a custom pointer more persuasive (as requested by a user). + +27. Wrapped the definitions of fileno and isatty for Windows, which appear in + pcretest.c, inside #ifndefs, because it seems they are sometimes already + pre-defined. + +28. Added support for (*UTF8) at the start of a pattern. + +29. Arrange for flags added by the "release type" setting in CMake to be shown + in the configuration summary. + + +Version 7.8 05-Sep-08 +--------------------- + +1. Replaced UCP searching code with optimized version as implemented for Ad + Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two- + stage table and inline lookup instead of a function, giving speed ups of 2 + to 5 times on some simple patterns that I tested. Permission was given to + distribute the MultiStage2.py script that generates the tables (it's not in + the tarball, but is in the Subversion repository). + +2. Updated the Unicode datatables to Unicode 5.1.0. This adds yet more + scripts. + +3. Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained + a group with a zero qualifier. The result of the study could be incorrect, + or the function might crash, depending on the pattern. + +4. Caseless matching was not working for non-ASCII characters in back + references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}. + It now works when Unicode Property Support is available. + +5. In pcretest, an escape such as \x{de} in the data was always generating + a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in + non-UTF-8 mode. If the value is greater than 255, it gives a warning about + truncation. + +6. Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...). + +7. Added two (int) casts to pcregrep when printing the difference of two + pointers, in case they are 64-bit values. + +8. Added comments about Mac OS X stack usage to the pcrestack man page and to + test 2 if it fails. + +9. Added PCRE_CALL_CONVENTION just before the names of all exported functions, + and a #define of that name to empty if it is not externally set. This is to + allow users of MSVC to set it if necessary. + +10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from + the convenience functions in the pcre_get.c source file. + +11. An option change at the start of a pattern that had top-level alternatives + could cause overwriting and/or a crash. This command provoked a crash in + some environments: + + printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest + + This potential security problem was recorded as CVE-2008-2371. + +12. For a pattern where the match had to start at the beginning or immediately + after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and + pcre_dfa_exec() could read past the end of the passed subject if there was + no match. To help with detecting such bugs (e.g. with valgrind), I modified + pcretest so that it places the subject at the end of its malloc-ed buffer. + +13. The change to pcretest in 12 above threw up a couple more cases when pcre_ + exec() might read past the end of the data buffer in UTF-8 mode. + +14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and + the data contained the byte 0x85 as part of a UTF-8 character within its + first line. This applied both to normal and DFA matching. + +15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example, + /^[^d]*?$/8 failed to match "abc". + +16. Added a missing copyright notice to pcrecpp_internal.h. + +17. Make it more clear in the documentation that values returned from + pcre_exec() in ovector are byte offsets, not character counts. + +18. Tidied a few places to stop certain compilers from issuing warnings. + +19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as + supplied by Stefan Weber. I made a further small update for 7.8 because + there is a change of source arrangements: the pcre_searchfuncs.c module is + replaced by pcre_ucd.c. + + +Version 7.7 07-May-08 +--------------------- + +1. Applied Craig's patch to sort out a long long problem: "If we can't convert + a string to a long long, pretend we don't even have a long long." This is + done by checking for the strtoq, strtoll, and _strtoi64 functions. + +2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with + pre-7.6 versions, which defined a global no_arg variable instead of putting + it in the RE class. (See also #8 below.) + +3. Remove a line of dead code, identified by coverity and reported by Nuno + Lopes. + +4. Fixed two related pcregrep bugs involving -r with --include or --exclude: + + (1) The include/exclude patterns were being applied to the whole pathnames + of files, instead of just to the final components. + + (2) If there was more than one level of directory, the subdirectories were + skipped unless they satisfied the include/exclude conditions. This is + inconsistent with GNU grep (and could even be seen as contrary to the + pcregrep specification - which I improved to make it absolutely clear). + The action now is always to scan all levels of directory, and just + apply the include/exclude patterns to regular files. + +5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used + --exclude_dir in the tests to avoid scanning .svn directories. + +6. Applied Craig's patch to the QuoteMeta function so that it escapes the + NUL character as backslash + 0 rather than backslash + NUL, because PCRE + doesn't support NULs in patterns. + +7. Added some missing "const"s to declarations of static tables in + pcre_compile.c and pcre_dfa_exec.c. + +8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was + caused by fix #2 above. (Subsequently also a second patch to fix the + first patch. And a third patch - this was a messy problem.) + +9. Applied Craig's patch to remove the use of push_back(). + +10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX + matching function regexec(). + +11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n', + which, however, unlike Perl's \g{...}, are subroutine calls, not back + references. PCRE supports relative numbers with this syntax (I don't think + Oniguruma does). + +12. Previously, a group with a zero repeat such as (...){0} was completely + omitted from the compiled regex. However, this means that if the group + was called as a subroutine from elsewhere in the pattern, things went wrong + (an internal error was given). Such groups are now left in the compiled + pattern, with a new opcode that causes them to be skipped at execution + time. + +13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes + to the way PCRE behaves: + + (a) A lone ] character is dis-allowed (Perl treats it as data). + + (b) A back reference to an unmatched subpattern matches an empty string + (Perl fails the current match path). + + (c) A data ] in a character class must be notated as \] because if the + first data character in a class is ], it defines an empty class. (In + Perl it is not possible to have an empty class.) The empty class [] + never matches; it forces failure and is equivalent to (*FAIL) or (?!). + The negative empty class [^] matches any one character, independently + of the DOTALL setting. + +14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a + non-existent subpattern following a character class starting with ']' and + containing () gave an internal compiling error instead of "reference to + non-existent subpattern". Fortunately, when the pattern did exist, the + compiled code was correct. (When scanning forwards to check for the + existence of the subpattern, it was treating the data ']' as terminating + the class, so got the count wrong. When actually compiling, the reference + was subsequently set up correctly.) + +15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile; + it was being rejected as not supported by pcre_dfa_exec(), even though + other assertions are supported. I have made pcre_dfa_exec() support + (*FAIL). + +16. The implementation of 13c above involved the invention of a new opcode, + OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s + cannot be changed at match time, I realized I could make a small + improvement to matching performance by compiling OP_ALLANY instead of + OP_ANY for "." when DOTALL was set, and then removing the runtime tests + on the OP_ANY path. + +17. Compiling pcretest on Windows with readline support failed without the + following two fixes: (1) Make the unistd.h include conditional on + HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno. + +18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the + ncurses library to be included for pcretest when ReadLine support is + requested, but also to allow for it to be overridden. This patch came from + Daniel Bergström. + +19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined + as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused + any errors with the current Unicode tables. Thanks to Peter Kankowski for + spotting this. + + +Version 7.6 28-Jan-08 +--------------------- + +1. A character class containing a very large number of characters with + codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer + overflow. + +2. Patch to cut out the "long long" test in pcrecpp_unittest when + HAVE_LONG_LONG is not defined. + +3. Applied Christian Ehrlicher's patch to update the CMake build files to + bring them up to date and include new features. This patch includes: + + - Fixed PH's badly added libz and libbz2 support. + - Fixed a problem with static linking. + - Added pcredemo. [But later removed - see 7 below.] + - Fixed dftables problem and added an option. + - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and + HAVE_LONG_LONG. + - Added readline support for pcretest. + - Added an listing of the option settings after cmake has run. + +4. A user submitted a patch to Makefile that makes it easy to create + "pcre.dll" under mingw when using Configure/Make. I added stuff to + Makefile.am that cause it to include this special target, without + affecting anything else. Note that the same mingw target plus all + the other distribution libraries and programs are now supported + when configuring with CMake (see 6 below) instead of with + Configure/Make. + +5. Applied Craig's patch that moves no_arg into the RE class in the C++ code. + This is an attempt to solve the reported problem "pcrecpp::no_arg is not + exported in the Windows port". It has not yet been confirmed that the patch + solves the problem, but it does no harm. + +6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and + NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured + with CMake, and also correct the comment about stack recursion. + +7. Remove the automatic building of pcredemo from the ./configure system and + from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example + of a program that users should build themselves after PCRE is installed, so + building it automatically is not really right. What is more, it gave + trouble in some build environments. + +8. Further tidies to CMakeLists.txt from Sheri and Christian. + + +Version 7.5 10-Jan-08 +--------------------- + +1. Applied a patch from Craig: "This patch makes it possible to 'ignore' + values in parens when parsing an RE using the C++ wrapper." + +2. Negative specials like \S did not work in character classes in UTF-8 mode. + Characters greater than 255 were excluded from the class instead of being + included. + +3. The same bug as (2) above applied to negated POSIX classes such as + [:^space:]. + +4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it + defined or documented. It seems to have been a typo for PCRE_STATIC, so + I have changed it. + +5. The construct (?&) was not diagnosed as a syntax error (it referenced the + first named subpattern) and a construct such as (?&a) would reference the + first named subpattern whose name started with "a" (in other words, the + length check was missing). Both these problems are fixed. "Subpattern name + expected" is now given for (?&) (a zero-length name), and this patch also + makes it give the same error for \k'' (previously it complained that that + was a reference to a non-existent subpattern). + +6. The erroneous patterns (?+-a) and (?-+a) give different error messages; + this is right because (?- can be followed by option settings as well as by + digits. I have, however, made the messages clearer. + +7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns + than the number used in the conditional) now cause a compile-time error. + This is actually not compatible with Perl, which accepts such patterns, but + treats the conditional as always being FALSE (as PCRE used to), but it + seems to me that giving a diagnostic is better. + +8. Change "alphameric" to the more common word "alphanumeric" in comments + and messages. + +9. Fix two occurrences of "backslash" in comments that should have been + "backspace". + +10. Remove two redundant lines of code that can never be obeyed (their function + was moved elsewhere). + +11. The program that makes PCRE's Unicode character property table had a bug + which caused it to generate incorrect table entries for sequences of + characters that have the same character type, but are in different scripts. + It amalgamated them into a single range, with the script of the first of + them. In other words, some characters were in the wrong script. There were + thirteen such cases, affecting characters in the following ranges: + + U+002b0 - U+002c1 + U+0060c - U+0060d + U+0061e - U+00612 + U+0064b - U+0065e + U+0074d - U+0076d + U+01800 - U+01805 + U+01d00 - U+01d77 + U+01d9b - U+01dbf + U+0200b - U+0200f + U+030fc - U+030fe + U+03260 - U+0327f + U+0fb46 - U+0fbb1 + U+10450 - U+1049d + +12. The -o option (show only the matching part of a line) for pcregrep was not + compatible with GNU grep in that, if there was more than one match in a + line, it showed only the first of them. It now behaves in the same way as + GNU grep. + +13. If the -o and -v options were combined for pcregrep, it printed a blank + line for every non-matching line. GNU grep prints nothing, and pcregrep now + does the same. The return code can be used to tell if there were any + non-matching lines. + +14. Added --file-offsets and --line-offsets to pcregrep. + +15. The pattern (?=something)(?R) was not being diagnosed as a potentially + infinitely looping recursion. The bug was that positive lookaheads were not + being skipped when checking for a possible empty match (negative lookaheads + and both kinds of lookbehind were skipped). + +16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the + inclusion of <windows.h> to before rather than after the definition of + INVALID_FILE_ATTRIBUTES (patch from David Byron). + +17. Specifying a possessive quantifier with a specific limit for a Unicode + character property caused pcre_compile() to compile bad code, which led at + runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this + are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that + caused the error; without that there was no problem. + +18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2. + +19. Added --enable-pcretest-libreadline. + +20. In pcrecpp.cc, the variable 'count' was incremented twice in + RE::GlobalReplace(). As a result, the number of replacements returned was + double what it should be. I removed one of the increments, but Craig sent a + later patch that removed the other one (the right fix) and added unit tests + that check the return values (which was not done before). + +21. Several CMake things: + + (1) Arranged that, when cmake is used on Unix, the libraries end up with + the names libpcre and libpcreposix, not just pcre and pcreposix. + + (2) The above change means that pcretest and pcregrep are now correctly + linked with the newly-built libraries, not previously installed ones. + + (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2. + +22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.* + crashed when matching a string such as a\x{2029}b (note that \x{2029} is a + UTF-8 newline character). The key issue is that the pattern starts .*; + this means that the match must be either at the beginning, or after a + newline. The bug was in the code for advancing after a failed match and + checking that the new position followed a newline. It was not taking + account of UTF-8 characters correctly. + +23. PCRE was behaving differently from Perl in the way it recognized POSIX + character classes. PCRE was not treating the sequence [:...:] as a + character class unless the ... were all letters. Perl, however, seems to + allow any characters between [: and :], though of course it rejects as + unknown any "names" that contain non-letters, because all the known class + names consist only of letters. Thus, Perl gives an error for [[:1234:]], + for example, whereas PCRE did not - it did not recognize a POSIX character + class. This seemed a bit dangerous, so the code has been changed to be + closer to Perl. The behaviour is not identical to Perl, because PCRE will + diagnose an unknown class for, for example, [[:l\ower:]] where Perl will + treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where + Perl does, and where it didn't before. + +24. Rewrite so as to remove the single use of %n from pcregrep because in some + Windows environments %n is disabled by default. + + +Version 7.4 21-Sep-07 +--------------------- + +1. Change 7.3/28 was implemented for classes by looking at the bitmap. This + means that a class such as [\s] counted as "explicit reference to CR or + LF". That isn't really right - the whole point of the change was to try to + help when there was an actual mention of one of the two characters. So now + the change happens only if \r or \n (or a literal CR or LF) character is + encountered. + +2. The 32-bit options word was also used for 6 internal flags, but the numbers + of both had grown to the point where there were only 3 bits left. + Fortunately, there was spare space in the data structure, and so I have + moved the internal flags into a new 16-bit field to free up more option + bits. + +3. The appearance of (?J) at the start of a pattern set the DUPNAMES option, + but did not set the internal JCHANGED flag - either of these is enough to + control the way the "get" function works - but the PCRE_INFO_JCHANGED + facility is supposed to tell if (?J) was ever used, so now (?J) at the + start sets both bits. + +4. Added options (at build time, compile time, exec time) to change \R from + matching any Unicode line ending sequence to just matching CR, LF, or CRLF. + +5. doc/pcresyntax.html was missing from the distribution. + +6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward + compatibility, even though it is no longer used. + +7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and + strtoull to pcrecpp.cc to select the available functions in WIN32 when the + windows.h file is present (where different names are used). [This was + reversed later after testing - see 16 below.] + +8. Changed all #include <config.h> to #include "config.h". There were also + some further <pcre.h> cases that I changed to "pcre.h". + +9. When pcregrep was used with the --colour option, it missed the line ending + sequence off the lines that it output. + +10. It was pointed out to me that arrays of string pointers cause lots of + relocations when a shared library is dynamically loaded. A technique of + using a single long string with a table of offsets can drastically reduce + these. I have refactored PCRE in four places to do this. The result is + dramatic: + + Originally: 290 + After changing UCP table: 187 + After changing error message table: 43 + After changing table of "verbs" 36 + After changing table of Posix names 22 + + Thanks to the folks working on Gregex for glib for this insight. + +11. --disable-stack-for-recursion caused compiling to fail unless -enable- + unicode-properties was also set. + +12. Updated the tests so that they work when \R is defaulted to ANYCRLF. + +13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously + checked only for CRLF. + +14. Added casts to pcretest.c to avoid compiler warnings. + +15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings. + +16. Added Craig's patch to remove the WINDOWS_H tests, that were not working, + and instead check for _strtoi64 explicitly, and avoid the use of snprintf() + entirely. This removes changes made in 7 above. + +17. The CMake files have been updated, and there is now more information about + building with CMake in the NON-UNIX-USE document. + + +Version 7.3 28-Aug-07 +--------------------- + + 1. In the rejigging of the build system that eventually resulted in 7.1, the + line "#include <pcre.h>" was included in pcre_internal.h. The use of angle + brackets there is not right, since it causes compilers to look for an + installed pcre.h, not the version that is in the source that is being + compiled (which of course may be different). I have changed it back to: + + #include "pcre.h" + + I have a vague recollection that the change was concerned with compiling in + different directories, but in the new build system, that is taken care of + by the VPATH setting the Makefile. + + 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed + when the subject happened to end in the byte 0x85 (e.g. if the last + character was \x{1ec5}). *Character* 0x85 is one of the "any" newline + characters but of course it shouldn't be taken as a newline when it is part + of another character. The bug was that, for an unlimited repeat of . in + not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by + characters when looking for a newline. + + 3. A small performance improvement in the DOTALL UTF-8 mode .* case. + + 4. Debugging: adjusted the names of opcodes for different kinds of parentheses + in debug output. + + 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for + long printing in the pcrecpp unittest when running under MinGW. + + 6. ESC_K was left out of the EBCDIC table. + + 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing + parentheses; I made it 1000, which seemed large enough. Unfortunately, the + limit also applies to "virtual nesting" when a pattern is recursive, and in + this case 1000 isn't so big. I have been able to remove this limit at the + expense of backing off one optimization in certain circumstances. Normally, + when pcre_exec() would call its internal match() function recursively and + immediately return the result unconditionally, it uses a "tail recursion" + feature to save stack. However, when a subpattern that can match an empty + string has an unlimited repetition quantifier, it no longer makes this + optimization. That gives it a stack frame in which to save the data for + checking that an empty string has been matched. Previously this was taken + from the 1000-entry workspace that had been reserved. So now there is no + explicit limit, but more stack is used. + + 8. Applied Daniel's patches to solve problems with the import/export magic + syntax that is required for Windows, and which was going wrong for the + pcreposix and pcrecpp parts of the library. These were overlooked when this + problem was solved for the main library. + + 9. There were some crude static tests to avoid integer overflow when computing + the size of patterns that contain repeated groups with explicit upper + limits. As the maximum quantifier is 65535, the maximum group length was + set at 30,000 so that the product of these two numbers did not overflow a + 32-bit integer. However, it turns out that people want to use groups that + are longer than 30,000 bytes (though not repeat them that many times). + Change 7.0/17 (the refactoring of the way the pattern size is computed) has + made it possible to implement the integer overflow checks in a much more + dynamic way, which I have now done. The artificial limitation on group + length has been removed - we now have only the limit on the total length of + the compiled pattern, which depends on the LINK_SIZE setting. + +10. Fixed a bug in the documentation for get/copy named substring when + duplicate names are permitted. If none of the named substrings are set, the + functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an + empty string. + +11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E + instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error, + because the ] is interpreted as the first data character and the + terminating ] is not found. PCRE has been made compatible with Perl in this + regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could + cause memory overwriting. + +10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty + string has been matched (to stop an infinite loop). It was not recognizing + a conditional subpattern that could match an empty string if that + subpattern was within another subpattern. For example, it looped when + trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the + condition was not nested. This bug has been fixed. + +12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack + past the start of the subject in the presence of bytes with the top bit + set, for example "\x8aBCD". + +13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE), + (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT). + +14. Optimized (?!) to (*FAIL). + +15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629. + This restricts code points to be within the range 0 to 0x10FFFF, excluding + the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the + full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still + does: it's just the validity check that is more restrictive. + +16. Inserted checks for integer overflows during escape sequence (backslash) + processing, and also fixed erroneous offset values for syntax errors during + backslash processing. + +17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above) + for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80". + +18. An unterminated class in a pattern like (?1)\c[ with a "forward reference" + caused an overrun. + +19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with + something other than just ASCII characters) inside a group that had an + unlimited repeat caused a loop at compile time (while checking to see + whether the group could match an empty string). + +20. Debugging a pattern containing \p or \P could cause a crash. For example, + [\P{Any}] did so. (Error in the code for printing property names.) + +21. An orphan \E inside a character class could cause a crash. + +22. A repeated capturing bracket such as (A)? could cause a wild memory + reference during compilation. + +23. There are several functions in pcre_compile() that scan along a compiled + expression for various reasons (e.g. to see if it's fixed length for look + behind). There were bugs in these functions when a repeated \p or \P was + present in the pattern. These operators have additional parameters compared + with \d, etc, and these were not being taken into account when moving along + the compiled data. Specifically: + + (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed + length. + + (b) An item such as \pL+ within a repeated group could cause crashes or + loops. + + (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect + "reference to non-existent subpattern" error. + + (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time. + +24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte + characters were involved (for example /\S{2}/8g with "A\x{a3}BC"). + +25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop. + +26. Patterns such as [\P{Yi}A] which include \p or \P and just one other + character were causing crashes (broken optimization). + +27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing + \p or \P) caused a compile-time loop. + +28. More problems have arisen in unanchored patterns when CRLF is a valid line + break. For example, the unstudied pattern [\r\n]A does not match the string + "\r\nA" because change 7.0/46 below moves the current point on by two + characters after failing to match at the start. However, the pattern \nA + *does* match, because it doesn't start till \n, and if [\r\n]A is studied, + the same is true. There doesn't seem any very clean way out of this, but + what I have chosen to do makes the common cases work: PCRE now takes note + of whether there can be an explicit match for \r or \n anywhere in the + pattern, and if so, 7.0/46 no longer applies. As part of this change, + there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled + pattern has explicit CR or LF references. + +29. Added (*CR) etc for changing newline setting at start of pattern. + + +Version 7.2 19-Jun-07 +--------------------- + + 1. If the fr_FR locale cannot be found for test 3, try the "french" locale, + which is apparently normally available under Windows. + + 2. Re-jig the pcregrep tests with different newline settings in an attempt + to make them independent of the local environment's newline setting. + + 3. Add code to configure.ac to remove -g from the CFLAGS default settings. + + 4. Some of the "internals" tests were previously cut out when the link size + was not 2, because the output contained actual offsets. The recent new + "Z" feature of pcretest means that these can be cut out, making the tests + usable with all link sizes. + + 5. Implemented Stan Switzer's goto replacement for longjmp() when not using + stack recursion. This gives a massive performance boost under BSD, but just + a small improvement under Linux. However, it saves one field in the frame + in all cases. + + 6. Added more features from the forthcoming Perl 5.10: + + (a) (?-n) (where n is a string of digits) is a relative subroutine or + recursion call. It refers to the nth most recently opened parentheses. + + (b) (?+n) is also a relative subroutine call; it refers to the nth next + to be opened parentheses. + + (c) Conditions that refer to capturing parentheses can be specified + relatively, for example, (?(-2)... or (?(+3)... + + (d) \K resets the start of the current match so that everything before + is not part of it. + + (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible). + + (f) \g{name} is another synonym - part of Perl 5.10's unification of + reference syntax. + + (g) (?| introduces a group in which the numbering of parentheses in each + alternative starts with the same number. + + (h) \h, \H, \v, and \V match horizontal and vertical whitespace. + + 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and + PCRE_INFO_JCHANGED. + + 8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not + terminating or by crashing. Diagnosed by Viktor Griph; it was in the code + for detecting groups that can match an empty string. + + 9. A pattern with a very large number of alternatives (more than several + hundred) was running out of internal workspace during the pre-compile + phase, where pcre_compile() figures out how much memory will be needed. A + bit of new cunning has reduced the workspace needed for groups with + alternatives. The 1000-alternative test pattern now uses 12 bytes of + workspace instead of running out of the 4096 that are available. + +10. Inserted some missing (unsigned int) casts to get rid of compiler warnings. + +11. Applied patch from Google to remove an optimization that didn't quite work. + The report of the bug said: + + pcrecpp::RE("a*").FullMatch("aaa") matches, while + pcrecpp::RE("a*?").FullMatch("aaa") does not, and + pcrecpp::RE("a*?\\z").FullMatch("aaa") does again. + +12. If \p or \P was used in non-UTF-8 mode on a character greater than 127 + it matched the wrong number of bytes. + + +Version 7.1 24-Apr-07 +--------------------- + + 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one + that is more "standard", making use of automake and other Autotools. There + is some re-arrangement of the files and adjustment of comments consequent + on this. + + 2. Part of the patch fixed a problem with the pcregrep tests. The test of -r + for recursive directory scanning broke on some systems because the files + are not scanned in any specific order and on different systems the order + was different. A call to "sort" has been inserted into RunGrepTest for the + approprate test as a short-term fix. In the longer term there may be an + alternative. + + 3. I had an email from Eric Raymond about problems translating some of PCRE's + man pages to HTML (despite the fact that I distribute HTML pages, some + people do their own conversions for various reasons). The problems + concerned the use of low-level troff macros .br and .in. I have therefore + removed all such uses from the man pages (some were redundant, some could + be replaced by .nf/.fi pairs). The 132html script that I use to generate + HTML has been updated to handle .nf/.fi and to complain if it encounters + .br or .in. + + 4. Updated comments in configure.ac that get placed in config.h.in and also + arranged for config.h to be included in the distribution, with the name + config.h.generic, for the benefit of those who have to compile without + Autotools (compare pcre.h, which is now distributed as pcre.h.generic). + + 5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan + Weber: (1) pcre_internal.h was missing some function renames; (2) updated + makevp.bat for the current PCRE, using the additional files + makevp_c.txt, makevp_l.txt, and pcregexp.pas. + + 6. A Windows user reported a minor discrepancy with test 2, which turned out + to be caused by a trailing space on an input line that had got lost in his + copy. The trailing space was an accident, so I've just removed it. + + 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told + that is needed. + + 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c) + as "const" (a) because they are and (b) because it helps the PHP + maintainers who have recently made a script to detect big data structures + in the php code that should be moved to the .rodata section. I remembered + to update Builducptable as well, so it won't revert if ucptable.h is ever + re-created. + + 9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c, + pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in + order to be able to cut out the UTF-8 tables in the latter when UTF-8 + support is not required. This saves 1.5-2K of code, which is important in + some applications. + + Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c + so as not to refer to the tables, even though these functions will never be + called when UTF-8 support is disabled. Otherwise there are problems with a + shared library. + +10. Fixed two bugs in the emulated memmove() function in pcre_internal.h: + + (a) It was defining its arguments as char * instead of void *. + + (b) It was assuming that all moves were upwards in memory; this was true + a long time ago when I wrote it, but is no longer the case. + + The emulated memove() is provided for those environments that have neither + memmove() nor bcopy(). I didn't think anyone used it these days, but that + is clearly not the case, as these two bugs were recently reported. + +11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt, + and Detrail to create the HTML documentation, the .txt form of the man + pages, and it removes trailing spaces from listed files. It also creates + pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter + case, it wraps all the #defines with #ifndefs. This script should be run + before "make dist". + +12. Fixed two fairly obscure bugs concerned with quantified caseless matching + with Unicode property support. + + (a) For a maximizing quantifier, if the two different cases of the + character were of different lengths in their UTF-8 codings (there are + some cases like this - I found 11), and the matching function had to + back up over a mixture of the two cases, it incorrectly assumed they + were both the same length. + + (b) When PCRE was configured to use the heap rather than the stack for + recursion during matching, it was not correctly preserving the data for + the other case of a UTF-8 character when checking ahead for a match + while processing a minimizing repeat. If the check also involved + matching a wide character, but failed, corruption could cause an + erroneous result when trying to check for a repeat of the original + character. + +13. Some tidying changes to the testing mechanism: + + (a) The RunTest script now detects the internal link size and whether there + is UTF-8 and UCP support by running ./pcretest -C instead of relying on + values substituted by "configure". (The RunGrepTest script already did + this for UTF-8.) The configure.ac script no longer substitutes the + relevant variables. + + (b) The debugging options /B and /D in pcretest show the compiled bytecode + with length and offset values. This means that the output is different + for different internal link sizes. Test 2 is skipped for link sizes + other than 2 because of this, bypassing the problem. Unfortunately, + there was also a test in test 3 (the locale tests) that used /B and + failed for link sizes other than 2. Rather than cut the whole test out, + I have added a new /Z option to pcretest that replaces the length and + offset values with spaces. This is now used to make test 3 independent + of link size. (Test 2 will be tidied up later.) + +14. If erroroffset was passed as NULL to pcre_compile, it provoked a + segmentation fault instead of returning the appropriate error message. + +15. In multiline mode when the newline sequence was set to "any", the pattern + ^$ would give a match between the \r and \n of a subject such as "A\r\nB". + This doesn't seem right; it now treats the CRLF combination as the line + ending, and so does not match in that case. It's only a pattern such as ^$ + that would hit this one: something like ^ABC$ would have failed after \r + and then tried again after \r\n. + +16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub" + in an attempt to make files that differ only in their line terminators + compare equal. This works on Linux. + +17. Under certain error circumstances pcregrep might try to free random memory + as it exited. This is now fixed, thanks to valgrind. + +19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string + "abc\r\n\r\n", it found an unwanted second match after the second \r. This + was because its rules for how to advance for /g after matching an empty + string at the end of a line did not allow for this case. They now check for + it specially. + +20. pcretest is supposed to handle patterns and data of any length, by + extending its buffers when necessary. It was getting this wrong when the + buffer for a data line had to be extended. + +21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or + CRLF as a newline sequence. + +22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut + out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but + I have nevertheless tidied it up. + +23. Added some casts to kill warnings from HP-UX ia64 compiler. + +24. Added a man page for pcre-config. + + +Version 7.0 19-Dec-06 +--------------------- + + 1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by + moving to gcc 4.1.1. + + 2. The -S option for pcretest uses setrlimit(); I had omitted to #include + sys/time.h, which is documented as needed for this function. It doesn't + seem to matter on Linux, but it showed up on some releases of OS X. + + 3. It seems that there are systems where bytes whose values are greater than + 127 match isprint() in the "C" locale. The "C" locale should be the + default when a C program starts up. In most systems, only ASCII printing + characters match isprint(). This difference caused the output from pcretest + to vary, making some of the tests fail. I have changed pcretest so that: + + (a) When it is outputting text in the compiled version of a pattern, bytes + other than 32-126 are always shown as hex escapes. + + (b) When it is outputting text that is a matched part of a subject string, + it does the same, unless a different locale has been set for the match + (using the /L modifier). In this case, it uses isprint() to decide. + + 4. Fixed a major bug that caused incorrect computation of the amount of memory + required for a compiled pattern when options that changed within the + pattern affected the logic of the preliminary scan that determines the + length. The relevant options are -x, and -i in UTF-8 mode. The result was + that the computed length was too small. The symptoms of this bug were + either the PCRE error "internal error: code overflow" from pcre_compile(), + or a glibc crash with a message such as "pcretest: free(): invalid next + size (fast)". Examples of patterns that provoked this bug (shown in + pcretest format) are: + + /(?-x: )/x + /(?x)(?-x: \s*#\s*)/ + /((?i)[\x{c0}])/8 + /(?i:[\x{c0}])/8 + + HOWEVER: Change 17 below makes this fix obsolete as the memory computation + is now done differently. + + 5. Applied patches from Google to: (a) add a QuoteMeta function to the C++ + wrapper classes; (b) implement a new function in the C++ scanner that is + more efficient than the old way of doing things because it avoids levels of + recursion in the regex matching; (c) add a paragraph to the documentation + for the FullMatch() function. + + 6. The escape sequence \n was being treated as whatever was defined as + "newline". Not only was this contrary to the documentation, which states + that \n is character 10 (hex 0A), but it also went horribly wrong when + "newline" was defined as CRLF. This has been fixed. + + 7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c) + was being set to -1 for the "end of line" case (supposedly a value that no + character can have). Though this value is never used (the check for end of + line is "zero bytes in current character"), it caused compiler complaints. + I've changed it to 0xffffffff. + + 8. In pcre_version.c, the version string was being built by a sequence of + C macros that, in the event of PCRE_PRERELEASE being defined as an empty + string (as it is for production releases) called a macro with an empty + argument. The C standard says the result of this is undefined. The gcc + compiler treats it as an empty string (which was what was wanted) but it is + reported that Visual C gives an error. The source has been hacked around to + avoid this problem. + + 9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows + builds of pcretest, and changed the call to _setmode() to use _O_BINARY + instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all + of them did). + +10. Originally, pcretest opened its input and output without "b"; then I was + told that "b" was needed in some environments, so it was added for release + 5.0 to both the input and output. (It makes no difference on Unix-like + systems.) Later I was told that it is wrong for the input on Windows. I've + now abstracted the modes into two macros, to make it easier to fiddle with + them, and removed "b" from the input mode under Windows. + +11. Added pkgconfig support for the C++ wrapper library, libpcrecpp. + +12. Added -help and --help to pcretest as an official way of being reminded + of the options. + +13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in + and pcrecpp.cc because they annoy compilers at high warning levels. + +14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop. + +15. Fixed an occurrence of == in configure.ac that should have been = (shell + scripts are not C programs :-) and which was not noticed because it works + on Linux. + +16. pcretest is supposed to handle any length of pattern and data line (as one + line or as a continued sequence of lines) by extending its input buffer if + necessary. This feature was broken for very long pattern lines, leading to + a string of junk being passed to pcre_compile() if the pattern was longer + than about 50K. + +17. I have done a major re-factoring of the way pcre_compile() computes the + amount of memory needed for a compiled pattern. Previously, there was code + that made a preliminary scan of the pattern in order to do this. That was + OK when PCRE was new, but as the facilities have expanded, it has become + harder and harder to keep it in step with the real compile phase, and there + have been a number of bugs (see for example, 4 above). I have now found a + cunning way of running the real compile function in a "fake" mode that + enables it to compute how much memory it would need, while actually only + ever using a few hundred bytes of working memory and without too many + tests of the mode. This should make future maintenance and development + easier. A side effect of this work is that the limit of 200 on the nesting + depth of parentheses has been removed (though this was never a serious + limitation, I suspect). However, there is a downside: pcre_compile() now + runs more slowly than before (30% or more, depending on the pattern). I + hope this isn't a big issue. There is no effect on runtime performance. + +18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a + newline (only possible for the last line of a file) and it was a + pattern that set a locale (followed by /Lsomething), pcretest crashed. + +19. Added additional timing features to pcretest. (1) The -tm option now times + matching only, not compiling. (2) Both -t and -tm can be followed, as a + separate command line item, by a number that specifies the number of + repeats to use when timing. The default is 50000; this gives better + precision, but takes uncomfortably long for very large patterns. + +20. Extended pcre_study() to be more clever in cases where a branch of a + subpattern has no definite first character. For example, (a*|b*)[cd] would + previously give no result from pcre_study(). Now it recognizes that the + first character must be a, b, c, or d. + +21. There was an incorrect error "recursive call could loop indefinitely" if + a subpattern (or the entire pattern) that was being tested for matching an + empty string contained only one non-empty item after a nested subpattern. + For example, the pattern (?>\x{100}*)\d(?R) provoked this error + incorrectly, because the \d was being skipped in the check. + +22. The pcretest program now has a new pattern option /B and a command line + option -b, which is equivalent to adding /B to every pattern. This causes + it to show the compiled bytecode, without the additional information that + -d shows. The effect of -d is now the same as -b with -i (and similarly, /D + is the same as /B/I). + +23. A new optimization is now able automatically to treat some sequences such + as a*b as a*+b. More specifically, if something simple (such as a character + or a simple class like \d) has an unlimited quantifier, and is followed by + something that cannot possibly match the quantified thing, the quantifier + is automatically "possessified". + +24. A recursive reference to a subpattern whose number was greater than 39 + went wrong under certain circumstances in UTF-8 mode. This bug could also + have affected the operation of pcre_study(). + +25. Realized that a little bit of performance could be had by replacing + (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters. + +26. Timing data from pcretest is now shown to 4 decimal places instead of 3. + +27. Possessive quantifiers such as a++ were previously implemented by turning + them into atomic groups such as ($>a+). Now they have their own opcodes, + which improves performance. This includes the automatically created ones + from 23 above. + +28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a + lookahead was broken if it was not anchored. PCRE was mistakenly expecting + the first matched character to be a colon. This applied both to named and + numbered groups. + +29. The ucpinternal.h header file was missing its idempotency #ifdef. + +30. I was sent a "project" file called libpcre.a.dev which I understand makes + building PCRE on Windows easier, so I have included it in the distribution. + +31. There is now a check in pcretest against a ridiculously large number being + returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G + loop, the loop is abandoned. + +32. Forward references to subpatterns in conditions such as (?(2)...) where + subpattern 2 is defined later cause pcre_compile() to search forwards in + the pattern for the relevant set of parentheses. This search went wrong + when there were unescaped parentheses in a character class, parentheses + escaped with \Q...\E, or parentheses in a #-comment in /x mode. + +33. "Subroutine" calls and backreferences were previously restricted to + referencing subpatterns earlier in the regex. This restriction has now + been removed. + +34. Added a number of extra features that are going to be in Perl 5.10. On the + whole, these are just syntactic alternatives for features that PCRE had + previously implemented using the Python syntax or my own invention. The + other formats are all retained for compatibility. + + (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well + as (?P<name>...). The new forms, as well as being in Perl 5.10, are + also .NET compatible. + + (b) A recursion or subroutine call to a named group can now be defined as + (?&name) as well as (?P>name). + + (c) A backreference to a named group can now be defined as \k<name> or + \k'name' as well as (?P=name). The new forms, as well as being in Perl + 5.10, are also .NET compatible. + + (d) A conditional reference to a named group can now use the syntax + (?(<name>) or (?('name') as well as (?(name). + + (e) A "conditional group" of the form (?(DEFINE)...) can be used to define + groups (named and numbered) that are never evaluated inline, but can be + called as "subroutines" from elsewhere. In effect, the DEFINE condition + is always false. There may be only one alternative in such a group. + + (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well + as the simple (?(R). The condition is true only if the most recent + recursion is that of the given number or name. It does not search out + through the entire recursion stack. + + (g) The escape \gN or \g{N} has been added, where N is a positive or + negative number, specifying an absolute or relative reference. + +35. Tidied to get rid of some further signed/unsigned compiler warnings and + some "unreachable code" warnings. + +36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other + things, this adds five new scripts. + +37. Perl ignores orphaned \E escapes completely. PCRE now does the same. + There were also incompatibilities regarding the handling of \Q..\E inside + character classes, for example with patterns like [\Qa\E-\Qz\E] where the + hyphen was adjacent to \Q or \E. I hope I've cleared all this up now. + +38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group + matches an empty string, and forcibly breaks the loop. There were bugs in + this code in non-simple cases. For a pattern such as ^(a()*)* matched + against aaaa the result was just "a" rather than "aaaa", for example. Two + separate and independent bugs (that affected different cases) have been + fixed. + +39. Refactored the code to abolish the use of different opcodes for small + capturing bracket numbers. This is a tidy that I avoided doing when I + removed the limit on the number of capturing brackets for 3.5 back in 2001. + The new approach is not only tidier, it makes it possible to reduce the + memory needed to fix the previous bug (38). + +40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline + sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when + processing dot, circumflex, or dollar metacharacters, or #-comments in /x + mode. + +41. Add \R to match any Unicode newline sequence, as suggested in the Unicode + report. + +42. Applied patch, originally from Ari Pollak, modified by Google, to allow + copy construction and assignment in the C++ wrapper. + +43. Updated pcregrep to support "--newline=any". In the process, I fixed a + couple of bugs that could have given wrong results in the "--newline=crlf" + case. + +44. Added a number of casts and did some reorganization of signed/unsigned int + variables following suggestions from Dair Grant. Also renamed the variable + "this" as "item" because it is a C++ keyword. + +45. Arranged for dftables to add + + #include "pcre_internal.h" + + to pcre_chartables.c because without it, gcc 4.x may remove the array + definition from the final binary if PCRE is built into a static library and + dead code stripping is activated. + +46. For an unanchored pattern, if a match attempt fails at the start of a + newline sequence, and the newline setting is CRLF or ANY, and the next two + characters are CRLF, advance by two characters instead of one. + + +Version 6.7 04-Jul-06 +--------------------- + + 1. In order to handle tests when input lines are enormously long, pcretest has + been re-factored so that it automatically extends its buffers when + necessary. The code is crude, but this _is_ just a test program. The + default size has been increased from 32K to 50K. + + 2. The code in pcre_study() was using the value of the re argument before + testing it for NULL. (Of course, in any sensible call of the function, it + won't be NULL.) + + 3. The memmove() emulation function in pcre_internal.h, which is used on + systems that lack both memmove() and bcopy() - that is, hardly ever - + was missing a "static" storage class specifier. + + 4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns + containing an extended class (one that cannot be represented by a bitmap + because it contains high-valued characters or Unicode property items, e.g. + [\pZ]). Almost always one would set UTF-8 mode when processing such a + pattern, but PCRE should not loop if you do not (it no longer does). + [Detail: two cases were found: (a) a repeated subpattern containing an + extended class; (b) a recursive reference to a subpattern that followed a + previous extended class. It wasn't skipping over the extended class + correctly when UTF-8 mode was not set.] + + 5. A negated single-character class was not being recognized as fixed-length + in lookbehind assertions such as (?<=[^f]), leading to an incorrect + compile error "lookbehind assertion is not fixed length". + + 6. The RunPerlTest auxiliary script was showing an unexpected difference + between PCRE and Perl for UTF-8 tests. It turns out that it is hard to + write a Perl script that can interpret lines of an input file either as + byte characters or as UTF-8, which is what "perltest" was being required to + do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you + can't do is switch easily at run time between having the "use utf8;" pragma + or not. In the end, I fudged it by using the RunPerlTest script to insert + "use utf8;" explicitly for the UTF-8 tests. + + 7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at + the end of the subject string, contrary to the documentation and to what + Perl does. This was true of both matching functions. Now it matches only at + the start of the subject and immediately after *internal* newlines. + + 8. A call of pcre_fullinfo() from pcretest to get the option bits was passing + a pointer to an int instead of a pointer to an unsigned long int. This + caused problems on 64-bit systems. + + 9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another + instance of the 'standard' template library not being so standard". + +10. There was no check on the number of named subpatterns nor the maximum + length of a subpattern name. The product of these values is used to compute + the size of the memory block for a compiled pattern. By supplying a very + long subpattern name and a large number of named subpatterns, the size + computation could be caused to overflow. This is now prevented by limiting + the length of names to 32 characters, and the number of named subpatterns + to 10,000. + +11. Subpatterns that are repeated with specific counts have to be replicated in + the compiled pattern. The size of memory for this was computed from the + length of the subpattern and the repeat count. The latter is limited to + 65535, but there was no limit on the former, meaning that integer overflow + could in principle occur. The compiled length of a repeated subpattern is + now limited to 30,000 bytes in order to prevent this. + +12. Added the optional facility to have named substrings with the same name. + +13. Added the ability to use a named substring as a condition, using the + Python syntax: (?(name)yes|no). This overloads (?(R)... and names that + are numbers (not recommended). Forward references are permitted. + +14. Added forward references in named backreferences (if you see what I mean). + +15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the + pattern could run off the end of the subject. For example, the pattern + "(?s)(.{1,5})"8 did this with the subject "ab". + +16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if + PCRE_CASELESS was set when matching characters that were quantified with ? + or *. + +17. A character class other than a single negated character that had a minimum + but no maximum quantifier - for example [ab]{6,} - was not handled + correctly by pce_dfa_exec(). It would match only one character. + +18. A valid (though odd) pattern that looked like a POSIX character + class but used an invalid character after [ (for example [[,abc,]]) caused + pcre_compile() to give the error "Failed: internal error: code overflow" or + in some cases to crash with a glibc free() error. This could even happen if + the pattern terminated after [[ but there just happened to be a sequence of + letters, a binary zero, and a closing ] in the memory that followed. + +19. Perl's treatment of octal escapes in the range \400 to \777 has changed + over the years. Originally (before any Unicode support), just the bottom 8 + bits were taken. Thus, for example, \500 really meant \100. Nowadays the + output from "man perlunicode" includes this: + + The regular expression compiler produces polymorphic opcodes. That + is, the pattern adapts to the data and automatically switches to + the Unicode character scheme when presented with Unicode data--or + instead uses a traditional byte scheme when presented with byte + data. + + Sadly, a wide octal escape does not cause a switch, and in a string with + no other multibyte characters, these octal escapes are treated as before. + Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern + /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a + Unicode string. + + I have not perpetrated such confusion in PCRE. Up till now, it took just + the bottom 8 bits, as in old Perl. I have now made octal escapes with + values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they + translate to the appropriate multibyte character. + +29. Applied some refactoring to reduce the number of warnings from Microsoft + and Borland compilers. This has included removing the fudge introduced + seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused + a warning about an unused variable. + +21. PCRE has not included VT (character 0x0b) in the set of whitespace + characters since release 4.0, because Perl (from release 5.004) does not. + [Or at least, is documented not to: some releases seem to be in conflict + with the documentation.] However, when a pattern was studied with + pcre_study() and all its branches started with \s, PCRE still included VT + as a possible starting character. Of course, this did no harm; it just + caused an unnecessary match attempt. + +22. Removed a now-redundant internal flag bit that recorded the fact that case + dependency changed within the pattern. This was once needed for "required + byte" processing, but is no longer used. This recovers a now-scarce options + bit. Also moved the least significant internal flag bit to the most- + significant bit of the word, which was not previously used (hangover from + the days when it was an int rather than a uint) to free up another bit for + the future. + +23. Added support for CRLF line endings as well as CR and LF. As well as the + default being selectable at build time, it can now be changed at runtime + via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to + specify that it is scanning data with non-default line endings. + +24. Changed the definition of CXXLINK to make it agree with the definition of + LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS. + +25. Applied Ian Taylor's patches to avoid using another stack frame for tail + recursions. This makes a big different to stack usage for some patterns. + +26. If a subpattern containing a named recursion or subroutine reference such + as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of + the space required for the compiled pattern went wrong and gave too small a + value. Depending on the environment, this could lead to "Failed: internal + error: code overflow at offset 49" or "glibc detected double free or + corruption" errors. + +27. Applied patches from Google (a) to support the new newline modes and (b) to + advance over multibyte UTF-8 characters in GlobalReplace. + +28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a + difference for some implementation of PCRE in some Windows version. + +29. Added some extra testing facilities to pcretest: + + \q<number> in a data line sets the "match limit" value + \Q<number> in a data line sets the "match recursion limt" value + -S <number> sets the stack size, where <number> is in megabytes + + The -S option isn't available for Windows. + + +Version 6.6 06-Feb-06 +--------------------- + + 1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined + in pcreposix.h. I have copied the definition from pcre.h. + + 2. Change 25 for 6.5 broke compilation in a build directory out-of-tree + because pcre.h is no longer a built file. + + 3. Added Jeff Friedl's additional debugging patches to pcregrep. These are + not normally included in the compiled code. + + +Version 6.5 01-Feb-06 +--------------------- + + 1. When using the partial match feature with pcre_dfa_exec(), it was not + anchoring the second and subsequent partial matches at the new starting + point. This could lead to incorrect results. For example, with the pattern + /1234/, partially matching against "123" and then "a4" gave a match. + + 2. Changes to pcregrep: + + (a) All non-match returns from pcre_exec() were being treated as failures + to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an + error message is output. Some extra information is given for the + PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are + probably the only errors that are likely to be caused by users (by + specifying a regex that has nested indefinite repeats, for instance). + If there are more than 20 of these errors, pcregrep is abandoned. + + (b) A binary zero was treated as data while matching, but terminated the + output line if it was written out. This has been fixed: binary zeroes + are now no different to any other data bytes. + + (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is + used to set a locale for matching. The --locale=xxxx long option has + been added (no short equivalent) to specify a locale explicitly on the + pcregrep command, overriding the environment variables. + + (d) When -B was used with -n, some line numbers in the output were one less + than they should have been. + + (e) Added the -o (--only-matching) option. + + (f) If -A or -C was used with -c (count only), some lines of context were + accidentally printed for the final match. + + (g) Added the -H (--with-filename) option. + + (h) The combination of options -rh failed to suppress file names for files + that were found from directory arguments. + + (i) Added the -D (--devices) and -d (--directories) options. + + (j) Added the -F (--fixed-strings) option. + + (k) Allow "-" to be used as a file name for -f as well as for a data file. + + (l) Added the --colo(u)r option. + + (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it + is not present by default. + + 3. A nasty bug was discovered in the handling of recursive patterns, that is, + items such as (?R) or (?1), when the recursion could match a number of + alternatives. If it matched one of the alternatives, but subsequently, + outside the recursion, there was a failure, the code tried to back up into + the recursion. However, because of the way PCRE is implemented, this is not + possible, and the result was an incorrect result from the match. + + In order to prevent this happening, the specification of recursion has + been changed so that all such subpatterns are automatically treated as + atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)). + + 4. I had overlooked the fact that, in some locales, there are characters for + which isalpha() is true but neither isupper() nor islower() are true. In + the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine + and ordfeminine) are like this. This affected the treatment of \w and \W + when they appeared in character classes, but not when they appeared outside + a character class. The bit map for "word" characters is now created + separately from the results of isalnum() instead of just taking it from the + upper, lower, and digit maps. (Plus the underscore character, of course.) + + 5. The above bug also affected the handling of POSIX character classes such as + [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's + permanent tables. Instead, the bit maps for such a class were previously + created as the appropriate unions of the upper, lower, and digit bitmaps. + Now they are created by subtraction from the [[:word:]] class, which has + its own bitmap. + + 6. The [[:blank:]] character class matches horizontal, but not vertical space. + It is created by subtracting the vertical space characters (\x09, \x0a, + \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the + subtraction was done in the overall bitmap for a character class, meaning + that a class such as [\x0c[:blank:]] was incorrect because \x0c would not + be recognized. This bug has been fixed. + + 7. Patches from the folks at Google: + + (a) pcrecpp.cc: "to handle a corner case that may or may not happen in + real life, but is still worth protecting against". + + (b) pcrecpp.cc: "corrects a bug when negative radixes are used with + regular expressions". + + (c) pcre_scanner.cc: avoid use of std::count() because not all systems + have it. + + (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by + "configure" and the latter not, in order to fix a problem somebody had + with compiling the Arg class on HP-UX. + + (e) Improve the error-handling of the C++ wrapper a little bit. + + (f) New tests for checking recursion limiting. + + 8. The pcre_memmove() function, which is used only if the environment does not + have a standard memmove() function (and is therefore rarely compiled), + contained two bugs: (a) use of int instead of size_t, and (b) it was not + returning a result (though PCRE never actually uses the result). + + 9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously + large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is + returned instead of calling malloc() with an overflowing number that would + most likely cause subsequent chaos. + +10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag. + +11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled + with this option is matched, the nmatch and pmatch options of regexec() are + ignored. + +12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is + provided in case anyone wants to the the POSIX interface with UTF-8 + strings. + +13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the + C++ linking (needed for some HP-UX environments). + +14. Avoid compiler warnings in get_ucpname() when compiled without UCP support + (unused parameter) and in the pcre_printint() function (omitted "default" + switch label when the default is to do nothing). + +15. Added some code to make it possible, when PCRE is compiled as a C++ + library, to replace subject pointers for pcre_exec() with a smart pointer + class, thus making it possible to process discontinuous strings. + +16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform + much the same function. They were added by different people who were trying + to make PCRE easy to compile on non-Unix systems. It has been suggested + that PCRE_EXPORT be abolished now that there is more automatic apparatus + for compiling on Windows systems. I have therefore replaced it with + PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it + defaults to "extern" for C or "extern C" for C++, which works fine on + Unix-like systems. It is now possible to override the value of PCRE_DATA_ + SCOPE with something explicit in config.h. In addition: + + (a) pcreposix.h still had just "extern" instead of either of these macros; + I have replaced it with PCRE_DATA_SCOPE. + + (b) Functions such as _pcre_xclass(), which are internal to the library, + but external in the C sense, all had PCRE_EXPORT in their definitions. + This is apparently wrong for the Windows case, so I have removed it. + (It makes no difference on Unix-like systems.) + +17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting + of recursive calls to match(). This is different to MATCH_LIMIT because + that limits the total number of calls to match(), not all of which increase + the depth of recursion. Limiting the recursion depth limits the amount of + stack (or heap if NO_RECURSE is set) that is used. The default can be set + when PCRE is compiled, and changed at run time. A patch from Google adds + this functionality to the C++ interface. + +18. Changes to the handling of Unicode character properties: + + (a) Updated the table to Unicode 4.1.0. + + (b) Recognize characters that are not in the table as "Cn" (undefined). + + (c) I revised the way the table is implemented to a much improved format + which includes recognition of ranges. It now supports the ranges that + are defined in UnicodeData.txt, and it also amalgamates other + characters into ranges. This has reduced the number of entries in the + table from around 16,000 to around 3,000, thus reducing its size + considerably. I realized I did not need to use a tree structure after + all - a binary chop search is just as efficient. Having reduced the + number of entries, I extended their size from 6 bytes to 8 bytes to + allow for more data. + + (d) Added support for Unicode script names via properties such as \p{Han}. + +19. In UTF-8 mode, a backslash followed by a non-Ascii character was not + matching that character. + +20. When matching a repeated Unicode property with a minimum greater than zero, + (for example \pL{2,}), PCRE could look past the end of the subject if it + reached it while seeking the minimum number of characters. This could + happen only if some of the characters were more than one byte long, because + there is a check for at least the minimum number of bytes. + +21. Refactored the implementation of \p and \P so as to be more general, to + allow for more different types of property in future. This has changed the + compiled form incompatibly. Anybody with saved compiled patterns that use + \p or \P will have to recompile them. + +22. Added "Any" and "L&" to the supported property types. + +23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode, + but give a compile time error if the value is greater than 0xff. + +24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were + accidentally not being installed or uninstalled. + +25. The pcre.h file was built from pcre.h.in, but the only changes that were + made were to insert the current release number. This seemed silly, because + it made things harder for people building PCRE on systems that don't run + "configure". I have turned pcre.h into a distributed file, no longer built + by "configure", with the version identification directly included. There is + no longer a pcre.h.in file. + + However, this change necessitated a change to the pcre-config script as + well. It is built from pcre-config.in, and one of the substitutions was the + release number. I have updated configure.ac so that ./configure now finds + the release number by grepping pcre.h. + +26. Added the ability to run the tests under valgrind. + + +Version 6.4 05-Sep-05 +--------------------- + + 1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines + "--" to be printed when multiple files were scanned, even when none of the + -A, -B, or -C options were used. This is not compatible with Gnu grep, so I + consider it to be a bug, and have restored the previous behaviour. + + 2. A couple of code tidies to get rid of compiler warnings. + + 3. The pcretest program used to cheat by referring to symbols in the library + whose names begin with _pcre_. These are internal symbols that are not + really supposed to be visible externally, and in some environments it is + possible to suppress them. The cheating is now confined to including + certain files from the library's source, which is a bit cleaner. + + 4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the + file's purpose clearer. + + 5. Reorganized pcre_ucp_findchar(). + + +Version 6.3 15-Aug-05 +--------------------- + + 1. The file libpcre.pc.in did not have general read permission in the tarball. + + 2. There were some problems when building without C++ support: + + (a) If C++ support was not built, "make install" and "make test" still + tried to test it. + + (b) There were problems when the value of CXX was explicitly set. Some + changes have been made to try to fix these, and ... + + (c) --disable-cpp can now be used to explicitly disable C++ support. + + (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a + backslash in a target when C++ was disabled. This confuses some + versions of "make", apparently. Using an intermediate variable solves + this. (Same for CPP_LOBJ.) + + 3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK) + (non-Windows) now includes $(CFLAGS) because these flags are sometimes + necessary on certain architectures. + + 4. Added a setting of -export-symbols-regex to the link command to remove + those symbols that are exported in the C sense, but actually are local + within the library, and not documented. Their names all begin with + "_pcre_". This is not a perfect job, because (a) we have to except some + symbols that pcretest ("illegally") uses, and (b) the facility isn't always + available (and never for static libraries). I have made a note to try to + find a way round (a) in the future. + + +Version 6.2 01-Aug-05 +--------------------- + + 1. There was no test for integer overflow of quantifier values. A construction + such as {1111111111111111} would give undefined results. What is worse, if + a minimum quantifier for a parenthesized subpattern overflowed and became + negative, the calculation of the memory size went wrong. This could have + led to memory overwriting. + + 2. Building PCRE using VPATH was broken. Hopefully it is now fixed. + + 3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like + operating environments where this matters. + + 4. Applied Giuseppe Maxia's patch to add additional features for controlling + PCRE options from within the C++ wrapper. + + 5. Named capturing subpatterns were not being correctly counted when a pattern + was compiled. This caused two problems: (a) If there were more than 100 + such subpatterns, the calculation of the memory needed for the whole + compiled pattern went wrong, leading to an overflow error. (b) Numerical + back references of the form \12, where the number was greater than 9, were + not recognized as back references, even though there were sufficient + previous subpatterns. + + 6. Two minor patches to pcrecpp.cc in order to allow it to compile on older + versions of gcc, e.g. 2.95.4. + + +Version 6.1 21-Jun-05 +--------------------- + + 1. There was one reference to the variable "posix" in pcretest.c that was not + surrounded by "#if !defined NOPOSIX". + + 2. Make it possible to compile pcretest without DFA support, UTF8 support, or + the cross-check on the old pcre_info() function, for the benefit of the + cut-down version of PCRE that is currently imported into Exim. + + 3. A (silly) pattern starting with (?i)(?-i) caused an internal space + allocation error. I've done the easy fix, which wastes 2 bytes for sensible + patterns that start (?i) but I don't think that matters. The use of (?i) is + just an example; this all applies to the other options as well. + + 4. Since libtool seems to echo the compile commands it is issuing, the output + from "make" can be reduced a bit by putting "@" in front of each libtool + compile command. + + 5. Patch from the folks at Google for configure.in to be a bit more thorough + in checking for a suitable C++ installation before trying to compile the + C++ stuff. This should fix a reported problem when a compiler was present, + but no suitable headers. + + 6. The man pages all had just "PCRE" as their title. I have changed them to + be the relevant file name. I have also arranged that these names are + retained in the file doc/pcre.txt, which is a concatenation in text format + of all the man pages except the little individual ones for each function. + + 7. The NON-UNIX-USE file had not been updated for the different set of source + files that come with release 6. I also added a few comments about the C++ + wrapper. + + +Version 6.0 07-Jun-05 +--------------------- + + 1. Some minor internal re-organization to help with my DFA experiments. + + 2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that + didn't matter for the library itself when fully configured, but did matter + when compiling without UCP support, or within Exim, where the ucp files are + not imported. + + 3. Refactoring of the library code to split up the various functions into + different source modules. The addition of the new DFA matching code (see + below) to a single monolithic source would have made it really too + unwieldy, quite apart from causing all the code to be include in a + statically linked application, when only some functions are used. This is + relevant even without the DFA addition now that patterns can be compiled in + one application and matched in another. + + The downside of splitting up is that there have to be some external + functions and data tables that are used internally in different modules of + the library but which are not part of the API. These have all had their + names changed to start with "_pcre_" so that they are unlikely to clash + with other external names. + + 4. Added an alternate matching function, pcre_dfa_exec(), which matches using + a different (DFA) algorithm. Although it is slower than the original + function, it does have some advantages for certain types of matching + problem. + + 5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(), + including restarting after a partial match. + + 6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not + defined when compiling for Windows was sent to me. I have put it into the + code, though I have no means of testing or verifying it. + + 7. Added the pcre_refcount() auxiliary function. + + 8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to + match before or at the first newline in the subject string. In pcretest, + the /f option on a pattern can be used to set this. + + 9. A repeated \w when used in UTF-8 mode with characters greater than 256 + would behave wrongly. This has been present in PCRE since release 4.0. + +10. A number of changes to the pcregrep command: + + (a) Refactored how -x works; insert ^(...)$ instead of setting + PCRE_ANCHORED and checking the length, in preparation for adding + something similar for -w. + + (b) Added the -w (match as a word) option. + + (c) Refactored the way lines are read and buffered so as to have more + than one at a time available. + + (d) Implemented a pcregrep test script. + + (e) Added the -M (multiline match) option. This allows patterns to match + over several lines of the subject. The buffering ensures that at least + 8K, or the rest of the document (whichever is the shorter) is available + for matching (and similarly the previous 8K for lookbehind assertions). + + (f) Changed the --help output so that it now says + + -w, --word-regex(p) + + instead of two lines, one with "regex" and the other with "regexp" + because that confused at least one person since the short forms are the + same. (This required a bit of code, as the output is generated + automatically from a table. It wasn't just a text change.) + + (g) -- can be used to terminate pcregrep options if the next thing isn't an + option but starts with a hyphen. Could be a pattern or a path name + starting with a hyphen, for instance. + + (h) "-" can be given as a file name to represent stdin. + + (i) When file names are being printed, "(standard input)" is used for + the standard input, for compatibility with GNU grep. Previously + "<stdin>" was used. + + (j) The option --label=xxx can be used to supply a name to be used for + stdin when file names are being printed. There is no short form. + + (k) Re-factored the options decoding logic because we are going to add + two more options that take data. Such options can now be given in four + different ways, e.g. "-fname", "-f name", "--file=name", "--file name". + + (l) Added the -A, -B, and -C options for requesting that lines of context + around matches be printed. + + (m) Added the -L option to print the names of files that do not contain + any matching lines, that is, the complement of -l. + + (n) The return code is 2 if any file cannot be opened, but pcregrep does + continue to scan other files. + + (o) The -s option was incorrectly implemented. For compatibility with other + greps, it now suppresses the error message for a non-existent or non- + accessible file (but not the return code). There is a new option called + -q that suppresses the output of matching lines, which was what -s was + previously doing. + + (p) Added --include and --exclude options to specify files for inclusion + and exclusion when recursing. + +11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly. + Hopefully, it now does. + +12. Missing cast in pcre_study(). + +13. Added an "uninstall" target to the makefile. + +14. Replaced "extern" in the function prototypes in Makefile.in with + "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix + world, but is set differently for Windows. + +15. Added a second compiling function called pcre_compile2(). The only + difference is that it has an extra argument, which is a pointer to an + integer error code. When there is a compile-time failure, this is set + non-zero, in addition to the error test pointer being set to point to an + error message. The new argument may be NULL if no error number is required + (but then you may as well call pcre_compile(), which is now just a + wrapper). This facility is provided because some applications need a + numeric error indication, but it has also enabled me to tidy up the way + compile-time errors are handled in the POSIX wrapper. + +16. Added VPATH=.libs to the makefile; this should help when building with one + prefix path and installing with another. (Or so I'm told by someone who + knows more about this stuff than I do.) + +17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This + passes PCRE_DOTALL to the pcre_compile() function, making the "." character + match everything, including newlines. This is not POSIX-compatible, but + somebody wanted the feature. From pcretest it can be activated by using + both the P and the s flags. + +18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one. + +19. libpcre.pc was being incorrectly installed as executable. + +20. A couple of places in pcretest check for end-of-line by looking for '\n'; + it now also looks for '\r' so that it will work unmodified on Windows. + +21. Added Google's contributed C++ wrapper to the distribution. + +22. Added some untidy missing memory free() calls in pcretest, to keep + Electric Fence happy when testing. + + + +Version 5.0 13-Sep-04 +--------------------- + + 1. Internal change: literal characters are no longer packed up into items + containing multiple characters in a single byte-string. Each character + is now matched using a separate opcode. However, there may be more than one + byte in the character in UTF-8 mode. + + 2. The pcre_callout_block structure has two new fields: pattern_position and + next_item_length. These contain the offset in the pattern to the next match + item, and its length, respectively. + + 3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic + insertion of callouts before each pattern item. Added the /C option to + pcretest to make use of this. + + 4. On the advice of a Windows user, the lines + + #if defined(_WIN32) || defined(WIN32) + _setmode( _fileno( stdout ), 0x8000 ); + #endif /* defined(_WIN32) || defined(WIN32) */ + + have been added to the source of pcretest. This apparently does useful + magic in relation to line terminators. + + 5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb" + for the benefit of those environments where the "b" makes a difference. + + 6. The icc compiler has the same options as gcc, but "configure" doesn't seem + to know about it. I have put a hack into configure.in that adds in code + to set GCC=yes if CC=icc. This seems to end up at a point in the + generated configure script that is early enough to affect the setting of + compiler options, which is what is needed, but I have no means of testing + whether it really works. (The user who reported this had patched the + generated configure script, which of course I cannot do.) + + LATER: After change 22 below (new libtool files), the configure script + seems to know about icc (and also ecc). Therefore, I have commented out + this hack in configure.in. + + 7. Added support for pkg-config (2 patches were sent in). + + 8. Negated POSIX character classes that used a combination of internal tables + were completely broken. These were [[:^alpha:]], [[:^alnum:]], and + [[:^ascii]]. Typically, they would match almost any characters. The other + POSIX classes were not broken in this way. + + 9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed + to find the match, as PCRE was deluded into thinking that the match had to + start at the start point or following a newline. The same bug applied to + patterns with negative forward assertions or any backward assertions + preceding ".*" at the start, unless the pattern required a fixed first + character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed. + +10. In UTF-8 mode, when moving forwards in the subject after a failed match + starting at the last subject character, bytes beyond the end of the subject + string were read. + +11. Renamed the variable "class" as "classbits" to make life easier for C++ + users. (Previously there was a macro definition, but it apparently wasn't + enough.) + +12. Added the new field "tables" to the extra data so that tables can be passed + in at exec time, or the internal tables can be re-selected. This allows + a compiled regex to be saved and re-used at a later time by a different + program that might have everything at different addresses. + +13. Modified the pcre-config script so that, when run on Solaris, it shows a + -R library as well as a -L library. + +14. The debugging options of pcretest (-d on the command line or D on a + pattern) showed incorrect output for anything following an extended class + that contained multibyte characters and which was followed by a quantifier. + +15. Added optional support for general category Unicode character properties + via the \p, \P, and \X escapes. Unicode property support implies UTF-8 + support. It adds about 90K to the size of the library. The meanings of the + inbuilt class escapes such as \d and \s have NOT been changed. + +16. Updated pcredemo.c to include calls to free() to release the memory for the + compiled pattern. + +17. The generated file chartables.c was being created in the source directory + instead of in the building directory. This caused the build to fail if the + source directory was different from the building directory, and was + read-only. + +18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE + file. No doubt somebody will tell me if they don't make sense... Also added + Dan Mooney's comments about building on OpenVMS. + +19. Added support for partial matching via the PCRE_PARTIAL option for + pcre_exec() and the \P data escape in pcretest. + +20. Extended pcretest with 3 new pattern features: + + (i) A pattern option of the form ">rest-of-line" causes pcretest to + write the compiled pattern to the file whose name is "rest-of-line". + This is a straight binary dump of the data, with the saved pointer to + the character tables forced to be NULL. The study data, if any, is + written too. After writing, pcretest reads a new pattern. + + (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a + compiled pattern from the given file. There must not be any + occurrences of "<" in the file name (pretty unlikely); if there are, + pcretest will instead treat the initial "<" as a pattern delimiter. + After reading in the pattern, pcretest goes on to read data lines as + usual. + + (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit + and 16-bit fields in a compiled pattern, to simulate a pattern that + was compiled on a host of opposite endianness. + +21. The pcre-exec() function can now cope with patterns that were compiled on + hosts of opposite endianness, with this restriction: + + As for any compiled expression that is saved and used later, the tables + pointer field cannot be preserved; the extra_data field in the arguments + to pcre_exec() should be used to pass in a tables address if a value + other than the default internal tables were used at compile time. + +22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is + now diagnosed as an error. Previously, most of the time, a negative number + would have been treated as zero, but if in addition "ovector" was passed as + NULL, a crash could occur. + +23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with + new versions from the libtool 1.5 distribution (the last one is a copy of + a file called libtool.m4). This seems to have fixed the need to patch + "configure" to support Darwin 1.3 (which I used to do). However, I still + had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my + workstation). + +24. Changed the PCRE licence to be the more standard "BSD" licence. + + +Version 4.5 01-Dec-03 +--------------------- + + 1. There has been some re-arrangement of the code for the match() function so + that it can be compiled in a version that does not call itself recursively. + Instead, it keeps those local variables that need separate instances for + each "recursion" in a frame on the heap, and gets/frees frames whenever it + needs to "recurse". Keeping track of where control must go is done by means + of setjmp/longjmp. The whole thing is implemented by a set of macros that + hide most of the details from the main code, and operates only if + NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the + "configure" mechanism, "--disable-stack-for-recursion" turns on this way of + operating. + + To make it easier for callers to provide specially tailored get/free + functions for this usage, two new functions, pcre_stack_malloc, and + pcre_stack_free, are used. They are always called in strict stacking order, + and the size of block requested is always the same. + + The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether + PCRE has been compiled to use the stack or the heap for recursion. The + -C option of pcretest uses this to show which version is compiled. + + A new data escape \S, is added to pcretest; it causes the amounts of store + obtained and freed by both kinds of malloc/free at match time to be added + to the output. + + 2. Changed the locale test to use "fr_FR" instead of "fr" because that's + what's available on my current Linux desktop machine. + + 3. When matching a UTF-8 string, the test for a valid string at the start has + been extended. If start_offset is not zero, PCRE now checks that it points + to a byte that is the start of a UTF-8 character. If not, it returns + PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked; + this is necessary because there may be backward assertions in the pattern. + When matching the same subject several times, it may save resources to use + PCRE_NO_UTF8_CHECK on all but the first call if the string is long. + + 4. The code for checking the validity of UTF-8 strings has been tightened so + that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings + containing "overlong sequences". + + 5. Fixed a bug (appearing twice) that I could not find any way of exploiting! + I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&" + should have been "&", but it just so happened that all the cases this let + through by mistake were picked up later in the function. + + 6. I had used a variable called "isblank" - this is a C99 function, causing + some compilers to warn. To avoid this, I renamed it (as "blankclass"). + + 7. Cosmetic: (a) only output another newline at the end of pcretest if it is + prompting; (b) run "./pcretest /dev/null" at the start of the test script + so the version is shown; (c) stop "make test" echoing "./RunTest". + + 8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems. + + 9. The prototype for memmove() for systems that don't have it was using + size_t, but the inclusion of the header that defines size_t was later. I've + moved the #includes for the C headers earlier to avoid this. + +10. Added some adjustments to the code to make it easier to compiler on certain + special systems: + + (a) Some "const" qualifiers were missing. + (b) Added the macro EXPORT before all exported functions; by default this + is defined to be empty. + (c) Changed the dftables auxiliary program (that builds chartables.c) so + that it reads its output file name as an argument instead of writing + to the standard output and assuming this can be redirected. + +11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character + class containing characters with values greater than 255, PCRE compilation + went into a loop. + +12. A recursive reference to a subpattern that was within another subpattern + that had a minimum quantifier of zero caused PCRE to crash. For example, + (x(y(?2))z)? provoked this bug with a subject that got as far as the + recursion. If the recursively-called subpattern itself had a zero repeat, + that was OK. + +13. In pcretest, the buffer for reading a data line was set at 30K, but the + buffer into which it was copied (for escape processing) was still set at + 1024, so long lines caused crashes. + +14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error + "internal error: code overflow...". This applied to any character class + that was followed by a possessive quantifier. + +15. Modified the Makefile to add libpcre.la as a prerequisite for + libpcreposix.la because I was told this is needed for a parallel build to + work. + +16. If a pattern that contained .* following optional items at the start was + studied, the wrong optimizing data was generated, leading to matching + errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any + matching string must start with a or b or c. The correct conclusion for + this pattern is that a match can start with any character. + + +Version 4.4 13-Aug-03 +--------------------- + + 1. In UTF-8 mode, a character class containing characters with values between + 127 and 255 was not handled correctly if the compiled pattern was studied. + In fixing this, I have also improved the studying algorithm for such + classes (slightly). + + 2. Three internal functions had redundant arguments passed to them. Removal + might give a very teeny performance improvement. + + 3. Documentation bug: the value of the capture_top field in a callout is *one + more than* the number of the hightest numbered captured substring. + + 4. The Makefile linked pcretest and pcregrep with -lpcre, which could result + in incorrectly linking with a previously installed version. They now link + explicitly with libpcre.la. + + 5. configure.in no longer needs to recognize Cygwin specially. + + 6. A problem in pcre.in for Windows platforms is fixed. + + 7. If a pattern was successfully studied, and the -d (or /D) flag was given to + pcretest, it used to include the size of the study block as part of its + output. Unfortunately, the structure contains a field that has a different + size on different hardware architectures. This meant that the tests that + showed this size failed. As the block is currently always of a fixed size, + this information isn't actually particularly useful in pcretest output, so + I have just removed it. + + 8. Three pre-processor statements accidentally did not start in column 1. + Sadly, there are *still* compilers around that complain, even though + standard C has not required this for well over a decade. Sigh. + + 9. In pcretest, the code for checking callouts passed small integers in the + callout_data field, which is a void * field. However, some picky compilers + complained about the casts involved for this on 64-bit systems. Now + pcretest passes the address of the small integer instead, which should get + rid of the warnings. + +10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at + both compile and run time, and gives an error if an invalid UTF-8 sequence + is found. There is a option for disabling this check in cases where the + string is known to be correct and/or the maximum performance is wanted. + +11. In response to a bug report, I changed one line in Makefile.in from + + -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \ + to + -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \ + + to look similar to other lines, but I have no way of telling whether this + is the right thing to do, as I do not use Windows. No doubt I'll get told + if it's wrong... + + +Version 4.3 21-May-03 +--------------------- + +1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the + Makefile. + +2. Some refactoring to improve the quality of the code: + + (i) The utf8_table... variables are now declared "const". + + (ii) The code for \cx, which used the "case flipping" table to upper case + lower case letters, now just substracts 32. This is ASCII-specific, + but the whole concept of \cx is ASCII-specific, so it seems + reasonable. + + (iii) PCRE was using its character types table to recognize decimal and + hexadecimal digits in the pattern. This is silly, because it handles + only 0-9, a-f, and A-F, but the character types table is locale- + specific, which means strange things might happen. A private + table is now used for this - though it costs 256 bytes, a table is + much faster than multiple explicit tests. Of course, the standard + character types table is still used for matching digits in subject + strings against \d. + + (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers + ending in _t are). So I've renamed it as ESC_tee. + +3. The first argument for regexec() in the POSIX wrapper should have been + defined as "const". + +4. Changed pcretest to use malloc() for its buffers so that they can be + Electric Fenced for debugging. + +5. There were several places in the code where, in UTF-8 mode, PCRE would try + to read one or more bytes before the start of the subject string. Often this + had no effect on PCRE's behaviour, but in some circumstances it could + provoke a segmentation fault. + +6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE + to try to read one or more bytes before the start of the subject string. + +7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with + UTF-8 support could misbehave in various ways if the subject string + contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind + area. (PCRE was not checking for the UTF-8 mode flag, and trying to move + back over UTF-8 characters.) + + +Version 4.2 14-Apr-03 +--------------------- + +1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed. + +2. Changes to the building process, supplied by Ronald Landheer-Cieslak + [ON_WINDOWS]: new variable, "#" on non-Windows platforms + [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms + [WIN_PREFIX]: new variable, "cyg" for Cygwin + * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT + and BUILD_EXEEXT + Note: automatic setting of the BUILD variables is not yet working + set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at + compile-time but not at link-time + [LINK]: use for linking executables only + make different versions for Windows and non-Windows + [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking + libraries + [LINK_FOR_BUILD]: new variable + [OBJEXT]: use throughout + [EXEEXT]: use throughout + <winshared>: new target + <wininstall>: new target + <dftables.o>: use native compiler + <dftables>: use native linker + <install>: handle Windows platform correctly + <clean>: ditto + <check>: ditto + copy DLL to top builddir before testing + + As part of these changes, -no-undefined was removed again. This was reported + to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea + in any case. + +3. Some tidies to get rid of compiler warnings: + + . In the match_data structure, match_limit was an unsigned long int, whereas + match_call_count was an int. I've made them both unsigned long ints. + + . In pcretest the fact that a const uschar * doesn't automatically cast to + a void * provoked a warning. + + . Turning on some more compiler warnings threw up some "shadow" variables + and a few more missing casts. + +4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8 + option, a class that contained a single character with a value between 128 + and 255 (e.g. /[\xFF]/) caused PCRE to crash. + +5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8 + option, a class that contained several characters, but with at least one + whose value was between 128 and 255 caused PCRE to crash. + + +Version 4.1 12-Mar-03 +--------------------- + +1. Compiling with gcc -pedantic found a couple of places where casts were +needed, and a string in dftables.c that was longer than standard compilers are +required to support. + +2. Compiling with Sun's compiler found a few more places where the code could +be tidied up in order to avoid warnings. + +3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the +first of these names is deprecated in the latest Autoconf in favour of the name +CC_FOR_BUILD, because "host" is typically used to mean the system on which the +compiled code will be run. I can't find a reference for HOST_CFLAGS, but by +analogy I have changed it to CFLAGS_FOR_BUILD. + +4. Added -no-undefined to the linking command in the Makefile, because this is +apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the +linking step for the pcreposix library. + +5. PCRE was failing to diagnose the case of two named groups with the same +name. + +6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a +literal character that is needed in the subject for a match, and scans along to +ensure that it is present before embarking on the full matching process. This +saves time in cases of nested unlimited repeats that are never going to match. +Problem: the scan can take a lot of time if the subject is very long (e.g. +megabytes), thus penalizing straightforward matches. It is now done only if the +amount of subject to be scanned is less than 1000 bytes. + +7. A lesser problem with the same optimization is that it was recording the +first character of an anchored pattern as "needed", thus provoking a search +right along the subject, even when the first match of the pattern was going to +fail. The "needed" character is now not set for anchored patterns, unless it +follows something in the pattern that is of non-fixed length. Thus, it still +fulfils its original purpose of finding quick non-matches in cases of nested +unlimited repeats, but isn't used for simple anchored patterns such as /^abc/. + + +Version 4.0 17-Feb-03 +--------------------- + +1. If a comment in an extended regex that started immediately after a meta-item +extended to the end of string, PCRE compiled incorrect data. This could lead to +all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not. + +2. Moved to autoconf 2.53 and libtool 1.4.2. + +3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently, +the special perltest8 script is no longer needed - all the tests can be run +from a single perltest script. + +4. From 5.004, Perl has not included the VT character (0x0b) in the set defined +by \s. It has now been removed in PCRE. This means it isn't recognized as +whitespace in /x regexes too, which is the same as Perl. Note that the POSIX +class [:space:] *does* include VT, thereby creating a mess. + +5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only +space and tab. + +6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use +its new features into the main test script, reducing the number of scripts. + +7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions +were backward compatible, and made the (?i) apply to the whole pattern, as if +/i were given. Now it behaves more logically, and applies the option setting +only to what follows. PCRE has been changed to follow suit. However, if it +finds options settings right at the start of the pattern, it extracts them into +the global options, as before. Thus, they show up in the info data. + +8. Added support for the \Q...\E escape sequence. Characters in between are +treated as literals. This is slightly different from Perl in that $ and @ are +also handled as literals inside the quotes. In Perl, they will cause variable +interpolation. Note the following examples: + + Pattern PCRE matches Perl matches + + \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz + \Qabc\$xyz\E abc\$xyz abc\$xyz + \Qabc\E\$\Qxyz\E abc$xyz abc$xyz + +For compatibility with Perl, \Q...\E sequences are recognized inside character +classes as well as outside them. + +9. Re-organized 3 code statements in pcretest to avoid "overflow in +floating-point constant arithmetic" warnings from a Microsoft compiler. Added a +(size_t) cast to one statement in pcretest and one in pcreposix to avoid +signed/unsigned warnings. + +10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o +option for pcretest, so I've replaced it by a simple function that does just +that job. + +11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or +"pcregrep -". + +12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's +Java package. This provides some syntactic sugar for simple cases of what my +documentation calls "once-only subpatterns". A pattern such as x*+ is the same +as (?>x*). In other words, if what is inside (?>...) is just a single repeated +item, you can use this simplified notation. Note that only makes sense with +greedy quantifiers. Consequently, the use of the possessive quantifier forces +greediness, whatever the setting of the PCRE_UNGREEDY option. + +13. A change of greediness default within a pattern was not taking effect at +the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized +subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option +was abstracted outside. + +14. PCRE now supports the \G assertion. It is true when the current matching +position is at the start point of the match. This differs from \A when the +starting offset is non-zero. Used with the /g option of pcretest (or similar +code), it works in the same way as it does for Perl's /g option. If all +alternatives of a regex begin with \G, the expression is anchored to the start +match position, and the "anchored" flag is set in the compiled expression. + +15. Some bugs concerning the handling of certain option changes within patterns +have been fixed. These applied to options other than (?ims). For example, +"a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have +been the other way round. Some of this was related to change 7 above. + +16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX +features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/ +and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports +POSIX classes only within a class (e.g. /[[:alpha:]]/). + +17. Added support for Perl's \C escape. This matches one byte, even in UTF8 +mode. Unlike ".", it always matches newline, whatever the setting of +PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind +assertions. Perl allows it, but it doesn't (in general) work because it can't +calculate the length of the lookbehind. At least, that's the case for Perl +5.8.0 - I've been told they are going to document that it doesn't work in +future. + +18. Added an error diagnosis for escapes that PCRE does not support: these are +\L, \l, \N, \P, \p, \U, \u, and \X. + +19. Although correctly diagnosing a missing ']' in a character class, PCRE was +reading past the end of the pattern in cases such as /[abcd/. + +20. PCRE was getting more memory than necessary for patterns with classes that +contained both POSIX named classes and other characters, e.g. /[[:space:]abc/. + +21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for +compiling PCRE for use with Virtual Pascal. + +22. Small fix to the Makefile to make it work properly if the build is done +outside the source tree. + +23. Added a new extension: a condition to go with recursion. If a conditional +subpattern starts with (?(R) the "true" branch is used if recursion has +happened, whereas the "false" branch is used only at the top level. + +24. When there was a very long string of literal characters (over 255 bytes +without UTF support, over 250 bytes with UTF support), the computation of how +much memory was required could be incorrect, leading to segfaults or other +strange effects. + +25. PCRE was incorrectly assuming anchoring (either to start of subject or to +start of line for a non-DOTALL pattern) when a pattern started with (.*) and +there was a subsequent back reference to those brackets. This meant that, for +example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't +possible to check for precisely this case. All we can do is abandon the +optimization if .* occurs inside capturing brackets when there are any back +references whatsoever. (See below for a better fix that came later.) + +26. The handling of the optimization for finding the first character of a +non-anchored pattern, and for finding a character that is required later in the +match were failing in some cases. This didn't break the matching; it just +failed to optimize when it could. The way this is done has been re-implemented. + +27. Fixed typo in error message for invalid (?R item (it said "(?p"). + +28. Added a new feature that provides some of the functionality that Perl +provides with (?{...}). The facility is termed a "callout". The way it is done +in PCRE is for the caller to provide an optional function, by setting +pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a +global variable. By default it is unset, which disables all calling out. To get +the function called, the regex must include (?C) at appropriate points. This +is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C). +This provides a means of identifying different callout points. When PCRE +reaches such a point in the regex, if pcre_callout has been set, the external +function is called. It is provided with data in a structure called +pcre_callout_block, which is defined in pcre.h. If the function returns 0, +matching continues; if it returns a non-zero value, the match at the current +point fails. However, backtracking will occur if possible. [This was changed +later and other features added - see item 49 below.] + +29. pcretest is upgraded to test the callout functionality. It provides a +callout function that displays information. By default, it shows the start of +the match and the current position in the text. There are some new data escapes +to vary what happens: + + \C+ in addition, show current contents of captured substrings + \C- do not supply a callout function + \C!n return 1 when callout number n is reached + \C!n!m return 1 when callout number n is reached for the mth time + +30. If pcregrep was called with the -l option and just a single file name, it +output "<stdin>" if a match was found, instead of the file name. + +31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing +slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to +pcre_exec(). This saves a malloc/free per call. The default value of +POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold +when configuring. + +32. The default maximum size of a compiled pattern is 64K. There have been a +few cases of people hitting this limit. The code now uses macros to handle the +storing of links as offsets within the compiled pattern. It defaults to 2-byte +links, but this can be changed to 3 or 4 bytes by --with-link-size when +configuring. Tests 2 and 5 work only with 2-byte links because they output +debugging information about compiled patterns. + +33. Internal code re-arrangements: + +(a) Moved the debugging function for printing out a compiled regex into + its own source file (printint.c) and used #include to pull it into + pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two + separate copies. + +(b) Defined the list of op-code names for debugging as a macro in + internal.h so that it is next to the definition of the opcodes. + +(c) Defined a table of op-code lengths for simpler skipping along compiled + code. This is again a macro in internal.h so that it is next to the + definition of the opcodes. + +34. Added support for recursive calls to individual subpatterns, along the +lines of Robin Houston's patch (but implemented somewhat differently). + +35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to +allow it to read and process whole directories in Win32. This code was +contributed by Lionel Fourquaux; it has not been tested by me. + +36. Added support for named subpatterns. The Python syntax (?P<name>...) is +used to name a group. Names consist of alphanumerics and underscores, and must +be unique. Back references use the syntax (?P=name) and recursive calls use +(?P>name) which is a PCRE extension to the Python extension. Groups still have +numbers. The function pcre_fullinfo() can be used after compilation to extract +a name/number map. There are three relevant calls: + + PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map + PCRE_INFO_NAMECOUNT yields the number of entries + PCRE_INFO_NAMETABLE yields a pointer to the map. + +The map is a vector of fixed-size entries. The size of each entry depends on +the length of the longest name used. The first two bytes of each entry are the +group number, most significant byte first. There follows the corresponding +name, zero terminated. The names are in alphabetical order. + +37. Make the maximum literal string in the compiled code 250 for the non-UTF-8 +case instead of 255. Making it the same both with and without UTF-8 support +means that the same test output works with both. + +38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid +calling malloc() with a zero argument. + +39. Change 25 above had to resort to a heavy-handed test for the .* anchoring +optimization. I've improved things by keeping a bitmap of backreferences with +numbers 1-31 so that if .* occurs inside capturing brackets that are not in +fact referenced, the optimization can be applied. It is unlikely that a +relevant occurrence of .* (i.e. one which might indicate anchoring or forcing +the match to follow \n) will appear inside brackets with a number greater than +31, but if it does, any back reference > 31 suppresses the optimization. + +40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect +of disabling numbered capturing parentheses. Any opening parenthesis that is +not followed by ? behaves as if it were followed by ?: but named parentheses +can still be used for capturing (and they will acquire numbers in the usual +way). + +41. Redesigned the return codes from the match() function into yes/no/error so +that errors can be passed back from deep inside the nested calls. A malloc +failure while inside a recursive subpattern call now causes the +PCRE_ERROR_NOMEMORY return instead of quietly going wrong. + +42. It is now possible to set a limit on the number of times the match() +function is called in a call to pcre_exec(). This facility makes it possible to +limit the amount of recursion and backtracking, though not in a directly +obvious way, because the match() function is used in a number of different +circumstances. The count starts from zero for each position in the subject +string (for non-anchored patterns). The default limit is, for compatibility, a +large number, namely 10 000 000. You can change this in two ways: + +(a) When configuring PCRE before making, you can use --with-match-limit=n + to set a default value for the compiled library. + +(b) For each call to pcre_exec(), you can pass a pcre_extra block in which + a different value is set. See 45 below. + +If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT. + +43. Added a new function pcre_config(int, void *) to enable run-time extraction +of things that can be changed at compile time. The first argument specifies +what is wanted and the second points to where the information is to be placed. +The current list of available information is: + + PCRE_CONFIG_UTF8 + +The output is an integer that is set to one if UTF-8 support is available; +otherwise it is set to zero. + + PCRE_CONFIG_NEWLINE + +The output is an integer that it set to the value of the code that is used for +newline. It is either LF (10) or CR (13). + + PCRE_CONFIG_LINK_SIZE + +The output is an integer that contains the number of bytes used for internal +linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above. + + PCRE_CONFIG_POSIX_MALLOC_THRESHOLD + +The output is an integer that contains the threshold above which the POSIX +interface uses malloc() for output vectors. See item 31 above. + + PCRE_CONFIG_MATCH_LIMIT + +The output is an unsigned integer that contains the default limit of the number +of match() calls in a pcre_exec() execution. See 42 above. + +44. pcretest has been upgraded by the addition of the -C option. This causes it +to extract all the available output from the new pcre_config() function, and to +output it. The program then exits immediately. + +45. A need has arisen to pass over additional data with calls to pcre_exec() in +order to support additional features. One way would have been to define +pcre_exec2() (for example) with extra arguments, but this would not have been +extensible, and would also have required all calls to the original function to +be mapped to the new one. Instead, I have chosen to extend the mechanism that +is used for passing in "extra" data from pcre_study(). + +The pcre_extra structure is now exposed and defined in pcre.h. It currently +contains the following fields: + + flags a bitmap indicating which of the following fields are set + study_data opaque data from pcre_study() + match_limit a way of specifying a limit on match() calls for a specific + call to pcre_exec() + callout_data data for callouts (see 49 below) + +The flag bits are also defined in pcre.h, and are + + PCRE_EXTRA_STUDY_DATA + PCRE_EXTRA_MATCH_LIMIT + PCRE_EXTRA_CALLOUT_DATA + +The pcre_study() function now returns one of these new pcre_extra blocks, with +the actual study data pointed to by the study_data field, and the +PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as +before. That is, this change is entirely upwards-compatible and requires no +change to existing code. + +If you want to pass in additional data to pcre_exec(), you can either place it +in a pcre_extra block provided by pcre_study(), or create your own pcre_extra +block. + +46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a +data string contains the escape sequence \M, pcretest calls pcre_exec() several +times with different match limits, until it finds the minimum value needed for +pcre_exec() to complete. The value is then output. This can be instructive; for +most simple matches the number is quite small, but for pathological cases it +gets very large very quickly. + +47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It +returns the size of the data block pointed to by the study_data field in a +pcre_extra block, that is, the value that was passed as the argument to +pcre_malloc() when PCRE was getting memory in which to place the information +created by pcre_study(). The fourth argument should point to a size_t variable. +pcretest has been extended so that this information is shown after a successful +pcre_study() call when information about the compiled regex is being displayed. + +48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR) +because what follows is always an absolute path. (Later: it turns out that this +is more than cosmetic for MinGW, because it doesn't like empty path +components.) + +49. Some changes have been made to the callout feature (see 28 above): + +(i) A callout function now has three choices for what it returns: + + 0 => success, carry on matching + > 0 => failure at this point, but backtrack if possible + < 0 => serious error, return this value from pcre_exec() + + Negative values should normally be chosen from the set of PCRE_ERROR_xxx + values. In particular, returning PCRE_ERROR_NOMATCH forces a standard + "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for + use by callout functions. It will never be used by PCRE itself. + +(ii) The pcre_extra structure (see 45 above) has a void * field called + callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The + pcre_callout_block structure has a field of the same name. The contents of + the field passed in the pcre_extra structure are passed to the callout + function in the corresponding field in the callout block. This makes it + easier to use the same callout-containing regex from multiple threads. For + testing, the pcretest program has a new data escape + + \C*n pass the number n (may be negative) as callout_data + + If the callout function in pcretest receives a non-zero value as + callout_data, it returns that value. + +50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also, +there were some redundant $(CFLAGS) in commands that are now specified as +$(LINK), which already includes $(CFLAGS). + +51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE +has been compiled with UTF-8 support *and* pcre_compile() has been compiled +with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume +one-byte characters throughout. Note that case-insensitive matching applies +only to characters whose values are less than 256. PCRE doesn't support the +notion of cases for higher-valued characters. + +(i) A character class whose characters are all within 0-255 is handled as + a bit map, and the map is inverted for negative classes. Previously, a + character > 255 always failed to match such a class; however it should + match if the class was a negative one (e.g. [^ab]). This has been fixed. + +(ii) A negated character class with a single character < 255 is coded as + "not this character" (OP_NOT). This wasn't working properly when the test + character was multibyte, either singly or repeated. + +(iii) Repeats of multibyte characters are now handled correctly in UTF-8 + mode, for example: \x{100}{2,3}. + +(iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either + singly or repeated) now correctly test multibyte characters. However, + PCRE doesn't recognize any characters with values greater than 255 as + digits, spaces, or word characters. Such characters always match \D, \S, + and \W, and never match \d, \s, or \w. + +(v) Classes may now contain characters and character ranges with values + greater than 255. For example: [ab\x{100}-\x{400}]. + +(vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call + PCRE in UTF-8 mode. + +52. The info request value PCRE_INFO_FIRSTCHAR has been renamed +PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is +retained for backwards compatibility. (Note that LASTLITERAL is also a byte +value.) + +53. The single man page has become too large. I have therefore split it up into +a number of separate man pages. These also give rise to individual HTML pages; +these are now put in a separate directory, and there is an index.html page that +lists them all. Some hyperlinking between the pages has been installed. + +54. Added convenience functions for handling named capturing parentheses. + +55. Unknown escapes inside character classes (e.g. [\M]) and escapes that +aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also +true in PCRE, except when the PCRE_EXTENDED option is set, in which case they +are faulted. + +56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when +calling configure. These values are used when compiling the dftables.c program +which is run to generate the source of the default character tables. They +default to the values of CC and CFLAGS. If you are cross-compiling PCRE, +you will need to set these values. + +57. Updated the building process for Windows DLL, as provided by Fred Cox. + + +Version 3.9 02-Jan-02 +--------------------- + +1. A bit of extraneous text had somehow crept into the pcregrep documentation. + +2. If --disable-static was given, the building process failed when trying to +build pcretest and pcregrep. (For some reason it was using libtool to compile +them, which is not right, as they aren't part of the library.) + + +Version 3.8 18-Dec-01 +--------------------- + +1. The experimental UTF-8 code was completely screwed up. It was packing the +bytes in the wrong order. How dumb can you get? + + +Version 3.7 29-Oct-01 +--------------------- + +1. In updating pcretest to check change 1 of version 3.6, I screwed up. +This caused pcretest, when used on the test data, to segfault. Unfortunately, +this didn't happen under Solaris 8, where I normally test things. + +2. The Makefile had to be changed to make it work on BSD systems, where 'make' +doesn't seem to recognize that ./xxx and xxx are the same file. (This entry +isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made +this fix an hour or so after the initial 3.7 release.) + + +Version 3.6 23-Oct-01 +--------------------- + +1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if +offsets passed as NULL with zero offset count. + +2. The config.guess and config.sub files had not been updated when I moved to +the latest autoconf. + + +Version 3.5 15-Aug-01 +--------------------- + +1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that +had been forgotten. + +2. By using declared but undefined structures, we can avoid using "void" +definitions in pcre.h while keeping the internal definitions of the structures +private. + +3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a +user point of view, this means that both static and shared libraries are built +by default, but this can be individually controlled. More of the work of +handling this static/shared cases is now inside libtool instead of PCRE's make +file. + +4. The pcretest utility is now installed along with pcregrep because it is +useful for users (to test regexs) and by doing this, it automatically gets +relinked by libtool. The documentation has been turned into a man page, so +there are now .1, .txt, and .html versions in /doc. + +5. Upgrades to pcregrep: + (i) Added long-form option names like gnu grep. + (ii) Added --help to list all options with an explanatory phrase. + (iii) Added -r, --recursive to recurse into sub-directories. + (iv) Added -f, --file to read patterns from a file. + +6. pcre_exec() was referring to its "code" argument before testing that +argument for NULL (and giving an error if it was NULL). + +7. Upgraded Makefile.in to allow for compiling in a different directory from +the source directory. + +8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the +options bits, the pointer it was passed was to an int instead of to an unsigned +long int. This mattered only on 64-bit systems. + +9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is +generated) instead of pcre.in, which it its source. Also made the same change +in several of the .c files. + +10. A new release of gcc defines printf() as a macro, which broke pcretest +because it had an ifdef in the middle of a string argument for printf(). Fixed +by using separate calls to printf(). + +11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure +script, to force use of CR or LF instead of \n in the source. On non-Unix +systems, the value can be set in config.h. + +12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an +absolute limit. Changed the text of the error message to make this clear, and +likewise updated the man page. + +13. The limit of 99 on the number of capturing subpatterns has been removed. +The new limit is 65535, which I hope will not be a "real" limit. + + +Version 3.4 22-Aug-00 +--------------------- + +1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *. + +2. Diagnose condition (?(0) as an error instead of crashing on matching. + + +Version 3.3 01-Aug-00 +--------------------- + +1. If an octal character was given, but the value was greater than \377, it +was not getting masked to the least significant bits, as documented. This could +lead to crashes in some systems. + +2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats +the hyphen as a literal. PCRE used to give an error; it now behaves like Perl. + +3. Added the functions pcre_free_substring() and pcre_free_substring_list(). +These just pass their arguments on to (pcre_free)(), but they are provided +because some uses of PCRE bind it to non-C systems that can call its functions, +but cannot call free() or pcre_free() directly. + +4. Add "make test" as a synonym for "make check". Corrected some comments in +the Makefile. + +5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the +Makefile. + +6. Changed the name of pgrep to pcregrep, because Solaris has introduced a +command called pgrep for grepping around the active processes. + +7. Added the beginnings of support for UTF-8 character strings. + +8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and +RANLIB to ./ltconfig so that they are used by libtool. I think these are all +the relevant ones. (AR is not passed because ./ltconfig does its own figuring +out for the ar command.) + + +Version 3.2 12-May-00 +--------------------- + +This is purely a bug fixing release. + +1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead +of ZA. This was just one example of several cases that could provoke this bug, +which was introduced by change 9 of version 2.00. The code for breaking +infinite loops after an iteration that matches an empty string was't working +correctly. + +2. The pcretest program was not imitating Perl correctly for the pattern /a*/g +when matched against abbab (for example). After matching an empty string, it +wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this +caused it to match further down the string than it should. + +3. The code contained an inclusion of sys/types.h. It isn't clear why this +was there because it doesn't seem to be needed, and it causes trouble on some +systems, as it is not a Standard C header. It has been removed. + +4. Made 4 silly changes to the source to avoid stupid compiler warnings that +were reported on the Macintosh. The changes were from + + while ((c = *(++ptr)) != 0 && c != '\n'); +to + while ((c = *(++ptr)) != 0 && c != '\n') ; + +Totally extraordinary, but if that's what it takes... + +5. PCRE is being used in one environment where neither memmove() nor bcopy() is +available. Added HAVE_BCOPY and an autoconf test for it; if neither +HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which +assumes the way PCRE uses memmove() (always moving upwards). + +6. PCRE is being used in one environment where strchr() is not available. There +was only one use in pcre.c, and writing it out to avoid strchr() probably gives +faster code anyway. + + +Version 3.1 09-Feb-00 +--------------------- + +The only change in this release is the fixing of some bugs in Makefile.in for +the "install" target: + +(1) It was failing to install pcreposix.h. + +(2) It was overwriting the pcre.3 man page with the pcreposix.3 man page. + + +Version 3.0 01-Feb-00 +--------------------- + +1. Add support for the /+ modifier to perltest (to output $` like it does in +pcretest). + +2. Add support for the /g modifier to perltest. + +3. Fix pcretest so that it behaves even more like Perl for /g when the pattern +matches null strings. + +4. Fix perltest so that it doesn't do unwanted things when fed an empty +pattern. Perl treats empty patterns specially - it reuses the most recent +pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this +effect. + +5. The POSIX interface was broken in that it was just handing over the POSIX +captured string vector to pcre_exec(), but (since release 2.00) PCRE has +required a bigger vector, with some working space on the end. This means that +the POSIX wrapper now has to get and free some memory, and copy the results. + +6. Added some simple autoconf support, placing the test data and the +documentation in separate directories, re-organizing some of the +information files, and making it build pcre-config (a GNU standard). Also added +libtool support for building PCRE as a shared library, which is now the +default. + +7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and +09 are not valid octal constants. Single digits will be used for minor values +less than 10. + +8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that +existing programs that set these in the POSIX interface can use PCRE without +modification. + +9. Added a new function, pcre_fullinfo() with an extensible interface. It can +return all that pcre_info() returns, plus additional data. The pcre_info() +function is retained for compatibility, but is considered to be obsolete. + +10. Added experimental recursion feature (?R) to handle one common case that +Perl 5.6 will be able to do with (?p{...}). + +11. Added support for POSIX character classes like [:alpha:], which Perl is +adopting. + + +Version 2.08 31-Aug-99 +---------------------- + +1. When startoffset was not zero and the pattern began with ".*", PCRE was not +trying to match at the startoffset position, but instead was moving forward to +the next newline as if a previous match had failed. + +2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G, +and could get into a loop if a null string was matched other than at the start +of the subject. + +3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can +be distinguished at compile time, and for completeness also added PCRE_DATE. + +5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL +in GnuWin32 environments. + + +Version 2.07 29-Jul-99 +---------------------- + +1. The documentation is now supplied in plain text form and HTML as well as in +the form of man page sources. + +2. C++ compilers don't like assigning (void *) values to other pointer types. +In particular this affects malloc(). Although there is no problem in Standard +C, I've put in casts to keep C++ compilers happy. + +3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call +should be (const char *). + +4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may +be useful for non-Unix systems who don't want to bother with the POSIX stuff. +However, I haven't made this a standard facility. The documentation doesn't +mention it, and the Makefile doesn't support it. + +5. The Makefile now contains an "install" target, with editable destinations at +the top of the file. The pcretest program is not installed. + +6. pgrep -V now gives the PCRE version number and date. + +7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was +causing the entire string to be ignored, instead of just the last character. + +8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a +non-matching string, it can take a very, very long time, even for strings of +quite modest length, because of the nested recursion. PCRE now does better in +some of these cases. It does this by remembering the last required literal +character in the pattern, and pre-searching the subject to ensure it is present +before running the real match. In other words, it applies a heuristic to detect +some types of certain failure quickly, and in the above example, if presented +with a string that has no trailing " it gives "no match" very quickly. + +9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored; +other alternatives are tried instead. + + +Version 2.06 09-Jun-99 +---------------------- + +1. Change pcretest's output for amount of store used to show just the code +space, because the remainder (the data block) varies in size between 32-bit and +64-bit systems. + +2. Added an extra argument to pcre_exec() to supply an offset in the subject to +start matching at. This allows lookbehinds to work when searching for multiple +occurrences in a string. + +3. Added additional options to pcretest for testing multiple occurrences: + + /+ outputs the rest of the string that follows a match + /g loops for multiple occurrences, using the new startoffset argument + /G loops for multiple occurrences by passing an incremented pointer + +4. PCRE wasn't doing the "first character" optimization for patterns starting +with \b or \B, though it was doing it for other lookbehind assertions. That is, +it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with +the letter 'x'. On long subject strings, this gives a significant speed-up. + + +Version 2.05 21-Apr-99 +---------------------- + +1. Changed the type of magic_number from int to long int so that it works +properly on 16-bit systems. + +2. Fixed a bug which caused patterns starting with .* not to work correctly +when the subject string contained newline characters. PCRE was assuming +anchoring for such patterns in all cases, which is not correct because .* will +not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if +DOTALL is set at top level; otherwise it knows that patterns starting with .* +must be retried after every newline in the subject. + + +Version 2.04 18-Feb-99 +---------------------- + +1. For parenthesized subpatterns with repeats whose minimum was zero, the +computation of the store needed to hold the pattern was incorrect (too large). +If such patterns were nested a few deep, this could multiply and become a real +problem. + +2. Added /M option to pcretest to show the memory requirement of a specific +pattern. Made -m a synonym of -s (which does this globally) for compatibility. + +3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being +compiled in such a way that the backtracking after subsequent failure was +pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of +((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size. + + +Version 2.03 02-Feb-99 +---------------------- + +1. Fixed typo and small mistake in man page. + +2. Added 4th condition (GPL supersedes if conflict) and created separate +LICENCE file containing the conditions. + +3. Updated pcretest so that patterns such as /abc\/def/ work like they do in +Perl, that is the internal \ allows the delimiter to be included in the +pattern. Locked out the use of \ as a delimiter. If \ immediately follows +the final delimiter, add \ to the end of the pattern (to test the error). + +4. Added the convenience functions for extracting substrings after a successful +match. Updated pcretest to make it able to test these functions. + + +Version 2.02 14-Jan-99 +---------------------- + +1. Initialized the working variables associated with each extraction so that +their saving and restoring doesn't refer to uninitialized store. + +2. Put dummy code into study.c in order to trick the optimizer of the IBM C +compiler for OS/2 into generating correct code. Apparently IBM isn't going to +fix the problem. + +3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution +calls, and wasn't printing the correct value for compiling calls. Increased the +default value of LOOPREPEAT, and the number of significant figures in the +times. + +4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT. + +5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid +a building problem on Windows NT with a FAT file system. + + +Version 2.01 21-Oct-98 +---------------------- + +1. Changed the API for pcre_compile() to allow for the provision of a pointer +to character tables built by pcre_maketables() in the current locale. If NULL +is passed, the default tables are used. + + +Version 2.00 24-Sep-98 +---------------------- + +1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable +it any more. + +2. Allow quantification of (?>) groups, and make it work correctly. + +3. The first character computation wasn't working for (?>) groups. + +4. Correct the implementation of \Z (it is permitted to match on the \n at the +end of the subject) and add 5.005's \z, which really does match only at the +very end of the subject. + +5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater. + +6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and +DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005 +localized options. All options to pcre_study() were also removed. + +7. Add other new features from 5.005: + + $(?<= positive lookbehind + $(?<! negative lookbehind + (?imsx-imsx) added the unsetting capability + such a setting is global if at outer level; local otherwise + (?imsx-imsx:) non-capturing groups with option setting + (?(cond)re|re) conditional pattern matching + + A backreference to itself in a repeated group matches the previous + captured string. + +8. General tidying up of studying (both automatic and via "study") +consequential on the addition of new assertions. + +9. As in 5.005, unlimited repeated groups that could match an empty substring +are no longer faulted at compile time. Instead, the loop is forcibly broken at +runtime if any iteration does actually match an empty substring. + +10. Include the RunTest script in the distribution. + +11. Added tests from the Perl 5.005_02 distribution. This showed up a few +discrepancies, some of which were old and were also with respect to 5.004. They +have now been fixed. + + +Version 1.09 28-Apr-98 +---------------------- + +1. A negated single character class followed by a quantifier with a minimum +value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to +program crashes, or just wrong answers. This did not apply to negated classes +containing more than one character, or to minima other than one. + + +Version 1.08 27-Mar-98 +---------------------- + +1. Add PCRE_UNGREEDY to invert the greediness of quantifiers. + +2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The +latter must appear before anything that relies on it in the pattern. + + +Version 1.07 16-Feb-98 +---------------------- + +1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited +repeat of a potentially empty string). + + +Version 1.06 23-Jan-98 +---------------------- + +1. Added Markus Oberhumer's little patches for C++. + +2. Literal strings longer than 255 characters were broken. + + +Version 1.05 23-Dec-97 +---------------------- + +1. Negated character classes containing more than one character were failing if +PCRE_CASELESS was set at run time. + + +Version 1.04 19-Dec-97 +---------------------- + +1. Corrected the man page, where some "const" qualifiers had been omitted. + +2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with +input syntax. + +3. Fixed memory leak which occurred when a regex with back references was +matched with an offsets vector that wasn't big enough. The temporary memory +that is used in this case wasn't being freed if the match failed. + +4. Tidied pcretest to ensure it frees memory that it gets. + +5. Temporary memory was being obtained in the case where the passed offsets +vector was exactly big enough. + +6. Corrected definition of offsetof() from change 5 below. + +7. I had screwed up change 6 below and broken the rules for the use of +setjmp(). Now fixed. + + +Version 1.03 18-Dec-97 +---------------------- + +1. A erroneous regex with a missing opening parenthesis was correctly +diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes +on some systems. + +2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because +it was reported that one broken compiler failed on the former because "code" is +also an independent variable. + +3. The erroneous regex a[]b caused an array overrun reference. + +4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not +fail on data ending with that character. (It was going on too far, and checking +the next character, typically a binary zero.) This was specific to the +optimized code for single-character negative classes. + +5. Added a contributed patch from the TIN world which does the following: + + + Add an undef for memmove, in case the the system defines a macro for it. + + + Add a definition of offsetof(), in case there isn't one. (I don't know + the reason behind this - offsetof() is part of the ANSI standard - but + it does no harm). + + + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating + most of the places where whitespace preceded '#'. I have given up and + allowed the remaining 2 cases to be at the margin. + + + Rename some variables in pcre to eliminate shadowing. This seems very + pedantic, but does no harm, of course. + +6. Moved the call to setjmp() into its own function, to get rid of warnings +from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used. + +7. Constructs such as \d{8,} were compiling into the equivalent of +\d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the +outcome, but in this particular case used more store than had been allocated, +which caused the bug to be discovered because it threw up an internal error. + +8. The debugging code in both pcre and pcretest for outputting the compiled +form of a regex was going wrong in the case of back references followed by +curly-bracketed repeats. + + +Version 1.02 12-Dec-97 +---------------------- + +1. Typos in pcre.3 and comments in the source fixed. + +2. Applied a contributed patch to get rid of places where it used to remove +'const' from variables, and fixed some signed/unsigned and uninitialized +variable warnings. + +3. Added the "runtest" target to Makefile. + +4. Set default compiler flag to -O2 rather than just -O. + + +Version 1.01 19-Nov-97 +---------------------- + +1. PCRE was failing to diagnose unlimited repeat of empty string for patterns +like /([ab]*)*/, that is, for classes with more than one character in them. + +2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such +as /((?>a*))*/ (a PCRE_EXTRA facility). + + +Version 1.00 18-Nov-97 +---------------------- + +1. Added compile-time macros to support systems such as SunOS4 which don't have +memmove() or strerror() but have other things that can be used instead. + +2. Arranged that "make clean" removes the executables. + + +Version 0.99 27-Oct-97 +---------------------- + +1. Fixed bug in code for optimizing classes with only one character. It was +initializing a 32-byte map regardless, which could cause it to run off the end +of the memory it had got. + +2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction. + + +Version 0.98 22-Oct-97 +---------------------- + +1. Fixed bug in code for handling temporary memory usage when there are more +back references than supplied space in the ovector. This could cause segfaults. + + +Version 0.97 21-Oct-97 +---------------------- + +1. Added the \X "cut" facility, conditional on PCRE_EXTRA. + +2. Optimized negated single characters not to use a bit map. + +3. Brought error texts together as macro definitions; clarified some of them; +fixed one that was wrong - it said "range out of order" when it meant "invalid +escape sequence". + +4. Changed some char * arguments to const char *. + +5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX). + +6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in +pcretest. + + +Version 0.96 16-Oct-97 +---------------------- + +1. Added a simple "pgrep" utility to the distribution. + +2. Fixed an incompatibility with Perl: "{" is now treated as a normal character +unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}" +where "ddd" means "one or more decimal digits". + +3. Fixed serious bug. If a pattern had a back reference, but the call to +pcre_exec() didn't supply a large enough ovector to record the related +identifying subpattern, the match always failed. PCRE now remembers the number +of the largest back reference, and gets some temporary memory in which to save +the offsets during matching if necessary, in order to ensure that +backreferences always work. + +4. Increased the compatibility with Perl in a number of ways: + + (a) . no longer matches \n by default; an option PCRE_DOTALL is provided + to request this handling. The option can be set at compile or exec time. + + (b) $ matches before a terminating newline by default; an option + PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline + mode). The option can be set at compile or exec time. + + (c) The handling of \ followed by a digit other than 0 is now supposed to be + the same as Perl's. If the decimal number it represents is less than 10 + or there aren't that many previous left capturing parentheses, an octal + escape is read. Inside a character class, it's always an octal escape, + even if it is a single digit. + + (d) An escaped but undefined alphabetic character is taken as a literal, + unless PCRE_EXTRA is set. Currently this just reserves the remaining + escapes. + + (e) {0} is now permitted. (The previous item is removed from the compiled + pattern). + +5. Changed all the names of code files so that the basic parts are no longer +than 10 characters, and abolished the teeny "globals.c" file. + +6. Changed the handling of character classes; they are now done with a 32-byte +bit map always. + +7. Added the -d and /D options to pcretest to make it possible to look at the +internals of compilation without having to recompile pcre. + + +Version 0.95 23-Sep-97 +---------------------- + +1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or +\x20 at the start of a run of normal characters. These were being treated as +real characters, instead of the source characters being re-checked. + + +Version 0.94 18-Sep-97 +---------------------- + +1. The functions are now thread-safe, with the caveat that the global variables +containing pointers to malloc() and free() or alternative functions are the +same for all threads. + +2. Get pcre_study() to generate a bitmap of initial characters for non- +anchored patterns when this is possible, and use it if passed to pcre_exec(). + + +Version 0.93 15-Sep-97 +---------------------- + +1. /(b)|(:+)/ was computing an incorrect first character. + +2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(), +but not actually doing anything yet. + +3. Treat "-" characters in classes that cannot be part of ranges as literals, +as Perl does (e.g. [-az] or [az-]). + +4. Set the anchored flag if a branch starts with .* or .*? because that tests +all possible positions. + +5. Split up into different modules to avoid including unneeded functions in a +compiled binary. However, compile and exec are still in one module. The "study" +function is split off. + +6. The character tables are now in a separate module whose source is generated +by an auxiliary program - but can then be edited by hand if required. There are +now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or +toupper() in the code. + +7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and +make them global. Abolish the function for setting them, as the caller can now +set them directly. + + +Version 0.92 11-Sep-97 +---------------------- + +1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character +(e.g. /a{1,3}/) was broken (I mis-optimized it). + +2. Caseless matching was not working in character classes if the characters in +the pattern were in upper case. + +3. Make ranges like [W-c] work in the same way as Perl for caseless matching. + +4. Make PCRE_ANCHORED public and accept as a compile option. + +5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and +PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to +pass them. + +6. Give an error if bad option bits passed at compile or run time. + +7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to +pcretest to cause it to pass that flag. + +8. Add pcre_info(), to get the number of identifying subpatterns, the stored +options, and the first character, if set. + +9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character. + + +Version 0.91 10-Sep-97 +---------------------- + +1. PCRE was failing to diagnose unlimited repeats of subpatterns that could +match the empty string as in /(a*)*/. It was looping and ultimately crashing. + +2. PCRE was looping on encountering an indefinitely repeated back reference to +a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what +Perl does - treats the match as successful. + +**** |