path: root/ChangeLog
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authorIvo De Decker <>2014-12-06 18:58:19 +0000
committerIvo De Decker <>2014-12-06 18:58:19 +0000
commitdd986e8b547c0dde924c4b566ad0894ad4f1beb9 (patch)
treea87ee49df2a732f2be8d1b3c9e46a341e6fb8698 /ChangeLog
pcre3 (2:8.35-3.3) unstable; urgency=medium
* Non-maintainer upload. * Upstream patch for heap buffer overflow, CVE-2014-8964, taken from 1:8.36-1 (Closes: #770478) Thanks to Salvatore Bonaccorso for the reminder. # imported from the archive
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+ChangeLog for PCRE
+Version 8.35 04-April-2014
+1. A new flag is set, when property checks are present in an XCLASS.
+ When this flag is not set, PCRE can perform certain optimizations
+ such as studying these XCLASS-es.
+2. The auto-possessification of character sets were improved: a normal
+ and an extended character set can be compared now. Furthermore
+ the JIT compiler optimizes more character set checks.
+3. Got rid of some compiler warnings for potentially uninitialized variables
+ that show up only when compiled with -O2.
+4. A pattern such as (?=ab\K) that uses \K in an assertion can set the start
+ of a match later then the end of the match. The pcretest program was not
+ handling the case sensibly - it was outputting from the start to the next
+ binary zero. It now reports this situation in a message, and outputs the
+ text from the end to the start.
+5. Fast forward search is improved in JIT. Instead of the first three
+ characters, any three characters with fixed position can be searched.
+ Search order: first, last, middle.
+6. Improve character range checks in JIT. Characters are read by an inprecise
+ function now, which returns with an unknown value if the character code is
+ above a certain treshold (e.g: 256). The only limitation is that the value
+ must be bigger than the treshold as well. This function is useful, when
+ the characters above the treshold are handled in the same way.
+7. The macros whose names start with RAWUCHAR are placeholders for a future
+ mode in which only the bottom 21 bits of 32-bit data items are used. To
+ make this more memorable for those maintaining the code, the names have
+ been changed to start with UCHAR21, and an extensive comment has been added
+ to their definition.
+8. Add missing (new) files sljitNativeTILEGX.c and sljitNativeTILEGX-encoder.c
+ to the export list in (they were accidentally omitted from the
+ 8.34 tarball).
+9. The informational output from pcretest used the phrase "starting byte set"
+ which is inappropriate for the 16-bit and 32-bit libraries. As the output
+ for "first char" and "need char" really means "non-UTF-char", I've changed
+ "byte" to "char", and slightly reworded the output. The documentation about
+ these values has also been (I hope) clarified.
+10. Another JIT related optimization: use table jumps for selecting the correct
+ backtracking path, when more than four alternatives are present inside a
+ bracket.
+11. Empty match is not possible, when the minimum length is greater than zero,
+ and there is no \K in the pattern. JIT should avoid empty match checks in
+ such cases.
+12. In a caseless character class with UCP support, when a character with more
+ than one alternative case was not the first character of a range, not all
+ the alternative cases were added to the class. For example, s and \x{17f}
+ are both alternative cases for S: the class [RST] was handled correctly,
+ but [R-T] was not.
+13. The file always checked for pthread support when JIT was
+ enabled. This is not used in Windows, so I have put this test inside a
+ check for the presence of windows.h (which was already tested for).
+14. Improve pattern prefix search by a simplified Boyer-Moore algorithm in JIT.
+ The algorithm provides a way to skip certain starting offsets, and usually
+ faster than linear prefix searches.
+15. Change 13 for 8.20 updated RunTest to check for the 'fr' locale as well
+ as for 'fr_FR' and 'french'. For some reason, however, it then used the
+ Windows-specific input and output files, which have 'french' screwed in.
+ So this could never have worked. One of the problems with locales is that
+ they aren't always the same. I have now updated RunTest so that it checks
+ the output of the locale test (test 3) against three different output
+ files, and it allows the test to pass if any one of them matches. With luck
+ this should make the test pass on some versions of Solaris where it was
+ failing. Because of the uncertainty, the script did not used to stop if
+ test 3 failed; it now does. If further versions of a French locale ever
+ come to light, they can now easily be added.
+16. If --with-pcregrep-bufsize was given a non-integer value such as "50K",
+ there was a message during ./configure, but it did not stop. This now
+ provokes an error. The invalid example in README has been corrected.
+ If a value less than the minimum is given, the minimum value has always
+ been used, but now a warning is given.
+17. If --enable-bsr-anycrlf was set, the special 16/32-bit test failed. This
+ was a bug in the test system, which is now fixed. Also, the list of various
+ configurations that are tested for each release did not have one with both
+ 16/32 bits and --enable-bar-anycrlf. It now does.
+18. pcretest was missing "-C bsr" for displaying the \R default setting.
+19. Little endian PowerPC systems are supported now by the JIT compiler.
+20. The fast forward newline mechanism could enter to an infinite loop on
+ certain invalid UTF-8 input. Although we don't support these cases
+ this issue can be fixed by a performance optimization.
+21. Change 33 of 8.34 is not sufficient to ensure stack safety because it does
+ not take account if existing stack usage. There is now a new global
+ variable called pcre_stack_guard that can be set to point to an external
+ function to check stack availability. It is called at the start of
+ processing every parenthesized group.
+22. A typo in the code meant that in ungreedy mode the max/min qualifier
+ behaved like a min-possessive qualifier, and, for example, /a{1,3}b/U did
+ not match "ab".
+23. When UTF was disabled, the JIT program reported some incorrect compile
+ errors. These messages are silenced now.
+24. Experimental support for ARM-64 and MIPS-64 has been added to the JIT
+ compiler.
+25. Change all the temporary files used in RunGrepTest to be different to those
+ used by RunTest so that the tests can be run simultaneously, for example by
+ "make -j check".
+Version 8.34 15-December-2013
+1. Add pcre[16|32]_jit_free_unused_memory to forcibly free unused JIT
+ executable memory. Patch inspired by Carsten Klein.
+2. ./configure --enable-coverage defined SUPPORT_GCOV in config.h, although
+ this macro is never tested and has no effect, because the work to support
+ coverage involves only compiling and linking options and special targets in
+ the Makefile. The comment in config.h implied that defining the macro would
+ enable coverage support, which is totally false. There was also support for
+ setting this macro in the CMake files (my fault, I just copied it from
+ configure). SUPPORT_GCOV has now been removed.
+3. Make a small performance improvement in strlen16() and strlen32() in
+ pcretest.
+4. Change 36 for 8.33 left some unreachable statements in pcre_exec.c,
+ detected by the Solaris compiler (gcc doesn't seem to be able to diagnose
+ these cases). There was also one in pcretest.c.
+5. Cleaned up a "may be uninitialized" compiler warning in pcre_exec.c.
+6. In UTF mode, the code for checking whether a group could match an empty
+ string (which is used for indefinitely repeated groups to allow for
+ breaking an infinite loop) was broken when the group contained a repeated
+ negated single-character class with a character that occupied more than one
+ data item and had a minimum repetition of zero (for example, [^\x{100}]* in
+ UTF-8 mode). The effect was undefined: the group might or might not be
+ deemed as matching an empty string, or the program might have crashed.
+7. The code for checking whether a group could match an empty string was not
+ recognizing that \h, \H, \v, \V, and \R must match a character.
+8. Implemented PCRE_INFO_MATCH_EMPTY, which yields 1 if the pattern can match
+ an empty string. If it can, pcretest shows this in its information output.
+9. Fixed two related bugs that applied to Unicode extended grapheme clusters
+ that were repeated with a maximizing qualifier (e.g. \X* or \X{2,5}) when
+ matched by pcre_exec() without using JIT:
+ (a) If the rest of the pattern did not match after a maximal run of
+ grapheme clusters, the code for backing up to try with fewer of them
+ did not always back up over a full grapheme when characters that do not
+ have the modifier quality were involved, e.g. Hangul syllables.
+ (b) If the match point in a subject started with modifier character, and
+ there was no match, the code could incorrectly back up beyond the match
+ point, and potentially beyond the first character in the subject,
+ leading to a segfault or an incorrect match result.
+10. A conditional group with an assertion condition could lead to PCRE
+ recording an incorrect first data item for a match if no other first data
+ item was recorded. For example, the pattern (?(?=ab)ab) recorded "a" as a
+ first data item, and therefore matched "ca" after "c" instead of at the
+ start.
+11. Change 40 for 8.33 (allowing pcregrep to find empty strings) showed up a
+ bug that caused the command "echo a | ./pcregrep -M '|a'" to loop.
+12. The source of pcregrep now includes z/OS-specific code so that it can be
+ compiled for z/OS as part of the special z/OS distribution.
+13. Added the -T and -TM options to pcretest.
+14. The code in pcre_compile.c for creating the table of named capturing groups
+ has been refactored. Instead of creating the table dynamically during the
+ actual compiling pass, the information is remembered during the pre-compile
+ pass (on the stack unless there are more than 20 named groups, in which
+ case malloc() is used) and the whole table is created before the actual
+ compile happens. This has simplified the code (it is now nearly 150 lines
+ shorter) and prepared the way for better handling of references to groups
+ with duplicate names.
+15. A back reference to a named subpattern when there is more than one of the
+ same name now checks them in the order in which they appear in the pattern.
+ The first one that is set is used for the reference. Previously only the
+ first one was inspected. This change makes PCRE more compatible with Perl.
+16. Unicode character properties were updated from Unicode 6.3.0.
+17. The compile-time code for auto-possessification has been refactored, based
+ on a patch by Zoltan Herczeg. It now happens after instead of during
+ compilation. The code is cleaner, and more cases are handled. The option
+ PCRE_NO_AUTO_POSSESS is added for testing purposes, and the -O and /O
+ options in pcretest are provided to set it. It can also be set by
+ (*NO_AUTO_POSSESS) at the start of a pattern.
+18. The character VT has been added to the default ("C" locale) set of
+ characters that match \s and are generally treated as white space,
+ following this same change in Perl 5.18. There is now no difference between
+ "Perl space" and "POSIX space". Whether VT is treated as white space in
+ other locales depends on the locale.
+19. The code for checking named groups as conditions, either for being set or
+ for being recursed, has been refactored (this is related to 14 and 15
+ above). Processing unduplicated named groups should now be as fast at
+ numerical groups, and processing duplicated groups should be faster than
+ before.
+20. Two patches to the CMake build system, by Alexander Barkov:
+ (1) Replace the "source" command by "." in CMakeLists.txt because
+ "source" is a bash-ism.
+ (2) Add missing HAVE_STDINT_H and HAVE_INTTYPES_H to;
+ without these the CMake build does not work on Solaris.
+21. Perl has changed its handling of \8 and \9. If there is no previously
+ encountered capturing group of those numbers, they are treated as the
+ literal characters 8 and 9 instead of a binary zero followed by the
+ literals. PCRE now does the same.
+22. Following Perl, added \o{} to specify codepoints in octal, making it
+ possible to specify values greater than 0777 and also making them
+ unambiguous.
+23. Perl now gives an error for missing closing braces after \x{... instead of
+ treating the string as literal. PCRE now does the same.
+24. RunTest used to grumble if an inappropriate test was selected explicitly,
+ but just skip it when running all tests. This make it awkward to run ranges
+ of tests when one of them was inappropriate. Now it just skips any
+ inappropriate tests, as it always did when running all tests.
+25. If PCRE_AUTO_CALLOUT and PCRE_UCP were set for a pattern that contained
+ character types such as \d or \w, too many callouts were inserted, and the
+ data that they returned was rubbish.
+26. In UCP mode, \s was not matching two of the characters that Perl matches,
+ namely NEL (U+0085) and MONGOLIAN VOWEL SEPARATOR (U+180E), though they
+ were matched by \h. The code has now been refactored so that the lists of
+ the horizontal and vertical whitespace characters used for \h and \v (which
+ are defined only in one place) are now also used for \s.
+27. Add JIT support for the 64 bit TileGX architecture.
+ Patch by Jiong Wang (Tilera Corporation).
+28. Possessive quantifiers for classes (both explicit and automatically
+ generated) now use special opcodes instead of wrapping in ONCE brackets.
+29. Whereas an item such as A{4}+ ignored the possessivenes of the quantifier
+ (because it's meaningless), this was not happening when PCRE_CASELESS was
+ set. Not wrong, but inefficient.
+30. Updated to add /u (force Unicode mode) when /W (use Unicode
+ properties for \w, \d, etc) is present in a test regex. Otherwise if the
+ test contains no characters greater than 255, Perl doesn't realise it
+ should be using Unicode semantics.
+31. Upgraded the handling of the POSIX classes [:graph:], [:print:], and
+ [:punct:] when PCRE_UCP is set so as to include the same characters as Perl
+ does in Unicode mode.
+32. Added the "forbid" facility to pcretest so that putting tests into the
+ wrong test files can sometimes be quickly detected.
+33. There is now a limit (default 250) on the depth of nesting of parentheses.
+ This limit is imposed to control the amount of system stack used at compile
+ time. It can be changed at build time by --with-parens-nest-limit=xxx or
+ the equivalent in CMake.
+34. Character classes such as [A-\d] or [a-[:digit:]] now cause compile-time
+ errors. Perl warns for these when in warning mode, but PCRE has no facility
+ for giving warnings.
+35. Change 34 for 8.13 allowed quantifiers on assertions, because Perl does.
+ However, this was not working for (?!) because it is optimized to (*FAIL),
+ for which PCRE does not allow quantifiers. The optimization is now disabled
+ when a quantifier follows (?!). I can't see any use for this, but it makes
+ things uniform.
+36. Perl no longer allows group names to start with digits, so I have made this
+ change also in PCRE. It simplifies the code a bit.
+37. In extended mode, Perl ignores spaces before a + that indicates a
+ possessive quantifier. PCRE allowed a space before the quantifier, but not
+ before the possessive +. It now does.
+38. The use of \K (reset reported match start) within a repeated possessive
+ group such as (a\Kb)*+ was not working.
+40. Document that the same character tables must be used at compile time and
+ run time, and that the facility to pass tables to pcre_exec() and
+ pcre_dfa_exec() is for use only with saved/restored patterns.
+41. Applied Jeff Trawick's patch CMakeLists.txt, which "provides two new
+ features for Builds with MSVC:
+ 1. Support pcre.rc and/or pcreposix.rc (as is already done for MinGW
+ builds). The .rc files can be used to set FileDescription and many other
+ attributes.
+ 2. Add an option (-DINSTALL_MSVC_PDB) to enable installation of .pdb files.
+ This allows higher-level build scripts which want .pdb files to avoid
+ hard-coding the exact files needed."
+42. Added support for [[:<:]] and [[:>:]] as used in the BSD POSIX library to
+ mean "start of word" and "end of word", respectively, as a transition aid.
+43. A minimizing repeat of a class containing codepoints greater than 255 in
+ non-UTF 16-bit or 32-bit modes caused an internal error when PCRE was
+ compiled to use the heap for recursion.
+44. Got rid of some compiler warnings for unused variables when UTF but not UCP
+ is configured.
+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 and 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 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
+ 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.)
+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 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,, and
+ 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 to put in more quoting round AC_LANG_PROGRAM etc. so
+ as not to get warnings when 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,, 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
+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 "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
+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 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, these
+ messages were output:
+ Consider adding `AC_CONFIG_MACRO_DIR([m4])' to and
+ rerunning libtoolize, to keep the correct libtool macros in-tree.
+ Consider adding `-I m4' to ACLOCAL_AMFLAGS in
+ 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
+, 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
+16. GNU libtool is named differently on some systems. The 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 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 ( 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 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 (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 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 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
+ - 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
+ 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, 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.
+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 and also for strtoll and
+ strtoull to 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 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 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
+ 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 that get placed 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 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 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
+ and 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 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 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 ( 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, 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
+ 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) "to handle a corner case that may or may not happen in
+ real life, but is still worth protecting against".
+ (b) "corrects a bug when negative radixes are used with
+ regular expressions".
+ (c) 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, 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 file.
+ However, this change necessitated a change to the pcre-config script as
+ well. It is built from, and one of the substitutions was the
+ release number. I have updated 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 as to go with; it also makes the
+ file's purpose clearer.
+ 5. Reorganized pcre_ucp_findchar().
+Version 6.3 15-Aug-05
+ 1. The file 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 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 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 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 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 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
+ 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, 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 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 as a prerequisite for
+ 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
+ 5. no longer needs to recognize Cygwin specially.
+ 6. A problem 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 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
+ * use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
+ 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
+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
+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
+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:
+The output is an integer that is set to one if UTF-8 support is available;
+otherwise it is set to zero.
+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).
+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.
+The output is an integer that contains the threshold above which the POSIX
+interface uses malloc() for output vectors. See item 31 above.
+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
+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
+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
+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
+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
+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
+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 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, 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
+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
+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');
+ 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 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
+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
+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
+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
+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
+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
+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
+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 *.
+6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
+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.