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ChangeLog for PCRE ------------------ Note that the PCRE 8.xx series (PCRE1) is now in a bugfix-only state. All development is happening in the PCRE2 10.xx series. Version 8.41 05-July-2017 ------------------------- 1. Fixed typo in CMakeLists.txt (wrong number of arguments for PCRE_STATIC_RUNTIME (affects MSVC only). 2. Issue 1 for 8.40 below was not correctly fixed. If pcregrep in multiline mode with --only-matching matched several lines, it restarted scanning at the next line instead of moving on to the end of the matched string, which can be several lines after the start. 3. Fix a missing else in the JIT compiler reported by 'idaifish'. 4. A (?# style comment is now ignored between a basic quantifier and a following '+' or '?' (example: /X+(?#comment)?Y/. 5. Avoid use of a potentially overflowing buffer in pcregrep (patch by Petr Pisar). 6. Fuzzers have reported issues in pcretest. These are NOT serious (it is, after all, just a test program). However, to stop the reports, some easy ones are fixed: (a) Check for values < 256 when calling isprint() in pcretest. (b) Give an error for too big a number after \O. 7. In the 32-bit library in non-UTF mode, an attempt to find a Unicode property for a character with a code point greater than 0x10ffff (the Unicode maximum) caused a crash. 8. The alternative matching function, pcre_dfa_exec() misbehaved if it encountered a character class with a possessive repeat, for example [a-f]{3}+. 9. When pcretest called pcre_copy_substring() in 32-bit mode, it set the buffer length incorrectly, which could result in buffer overflow. 10. Remove redundant line of code (accidentally left in ages ago). 11. Applied C++ patch from Irfan Adilovic to guard 'using std::' directives with namespace pcrecpp (Bugzilla #2084). 12. Remove a duplication typo in pcre_tables.c. 13. Fix returned offsets from regexec() when REG_STARTEND is used with a starting offset greater than zero. Version 8.40 11-January-2017 ---------------------------- 1. Using -o with -M in pcregrep could cause unnecessary repeated output when the match extended over a line boundary. 2. Applied Chris Wilson's second patch (Bugzilla #1681) to CMakeLists.txt for MSVC static compilation, putting the first patch under a new option. 3. Fix register overwite in JIT when SSE2 acceleration is enabled. 4. Ignore "show all captures" (/=) for DFA matching. 5. Fix JIT unaligned accesses on x86. Patch by Marc Mutz. 6. In any wide-character mode (8-bit UTF or any 16-bit or 32-bit mode), without PCRE_UCP set, a negative character type such as \D in a positive class should cause all characters greater than 255 to match, whatever else is in the class. There was a bug that caused this not to happen if a Unicode property item was added to such a class, for example [\D\P{Nd}] or [\W\pL]. 7. When pcretest was outputing information from a callout, the caret indicator for the current position in the subject line was incorrect if it was after an escape sequence for a character whose code point was greater than \x{ff}. 8. A pattern such as (?<RA>abc)(?(R)xyz) was incorrectly compiled such that the conditional was interpreted as a reference to capturing group 1 instead of a test for recursion. Any group whose name began with R was misinterpreted in this way. (The reference interpretation should only happen if the group's name is precisely "R".) 9. A number of bugs have been mended relating to match start-up optimizations when the first thing in a pattern is a positive lookahead. These all applied only when PCRE_NO_START_OPTIMIZE was *not* set: (a) A pattern such as (?=.*X)X$ was incorrectly optimized as if it needed both an initial 'X' and a following 'X'. (b) Some patterns starting with an assertion that started with .* were incorrectly optimized as having to match at the start of the subject or after a newline. There are cases where this is not true, for example, (?=.*[A-Z])(?=.{8,16})(?!.*[\s]) matches after the start in lines that start with spaces. Starting .* in an assertion is no longer taken as an indication of matching at the start (or after a newline). Version 8.39 14-June-2016 ------------------------- 1. If PCRE_AUTO_CALLOUT was set on a pattern that had a (?# comment between an item and its qualifier (for example, A(?#comment)?B) pcre_compile() misbehaved. This bug was found by the LLVM fuzzer. 2. Similar to the above, if an isolated \E was present between an item and its qualifier when PCRE_AUTO_CALLOUT was set, pcre_compile() misbehaved. This bug was found by the LLVM fuzzer. 3. Further to 8.38/46, negated classes such as [^[:^ascii:]\d] were also not working correctly in UCP mode. 4. The POSIX wrapper function regexec() crashed if the option REG_STARTEND was set when the pmatch argument was NULL. It now returns REG_INVARG. 5. Allow for up to 32-bit numbers in the ordin() function in pcregrep. 6. An empty \Q\E sequence between an item and its qualifier caused pcre_compile() to misbehave when auto callouts were enabled. This bug was found by the LLVM fuzzer. 7. If a pattern that was compiled with PCRE_EXTENDED started with white space or a #-type comment that was followed by (?-x), which turns off PCRE_EXTENDED, and there was no subsequent (?x) to turn it on again, pcre_compile() assumed that (?-x) applied to the whole pattern and consequently mis-compiled it. This bug was found by the LLVM fuzzer. 8. A call of pcre_copy_named_substring() for a named substring whose number was greater than the space in the ovector could cause a crash. 9. Yet another buffer overflow bug involved duplicate named groups with a group that reset capture numbers (compare 8.38/7 below). Once again, I have just allowed for more memory, even if not needed. (A proper fix is implemented in PCRE2, but it involves a lot of refactoring.) 10. pcre_get_substring_list() crashed if the use of \K in a match caused the start of the match to be earlier than the end. 11. Migrating appropriate PCRE2 JIT improvements to PCRE. 12. A pattern such as /(?<=((?C)0))/, which has a callout inside a lookbehind assertion, caused pcretest to generate incorrect output, and also to read uninitialized memory (detected by ASAN or valgrind). 13. A pattern that included (*ACCEPT) in the middle of a sufficiently deeply nested set of parentheses of sufficient size caused an overflow of the compiling workspace (which was diagnosed, but of course is not desirable). 14. And yet another buffer overflow bug involving duplicate named groups, this time nested, with a nested back reference. Yet again, I have just allowed for more memory, because anything more needs all the refactoring that has been done for PCRE2. An example pattern that provoked this bug is: /((?J)(?'R'(?'R'(?'R'(?'R'(?'R'(?|(\k'R'))))))))/ and the bug was registered as CVE-2016-1283. 15. pcretest went into a loop if global matching was requested with an ovector size less than 2. It now gives an error message. This bug was found by afl-fuzz. 16. An invalid pattern fragment such as (?(?C)0 was not diagnosing an error ("assertion expected") when (?(?C) was not followed by an opening parenthesis. 17. Fixed typo ("&&" for "&") in pcre_study(). Fortunately, this could not actually affect anything, by sheer luck. 18. Applied Chris Wilson's patch (Bugzilla #1681) to CMakeLists.txt for MSVC static compilation. 19. Modified the RunTest script to incorporate a valgrind suppressions file so that certain errors, provoked by the SSE2 instruction set when JIT is used, are ignored. 20. A racing condition is fixed in JIT reported by Mozilla. 21. Minor code refactor to avoid "array subscript is below array bounds" compiler warning. 22. Minor code refactor to avoid "left shift of negative number" warning. 23. Fix typo causing compile error when 16- or 32-bit JIT is compiled without UCP support. 24. Refactor to avoid compiler warnings in pcrecpp.cc. 25. Refactor to fix a typo in pcre_jit_test.c 26. Patch to support compiling pcrecpp.cc with Intel compiler. Version 8.38 23-November-2015 ----------------------------- 1. If a group that contained a recursive back reference also contained a forward reference subroutine call followed by a non-forward-reference subroutine call, for example /.((?2)(?R)\1)()/, pcre_compile() failed to compile correct code, leading to undefined behaviour or an internally detected error. This bug was discovered by the LLVM fuzzer. 2. Quantification of certain items (e.g. atomic back references) could cause incorrect code to be compiled when recursive forward references were involved. For example, in this pattern: /(?1)()((((((\1++))\x85)+)|))/. This bug was discovered by the LLVM fuzzer. 3. A repeated conditional group whose condition was a reference by name caused a buffer overflow if there was more than one group with the given name. This bug was discovered by the LLVM fuzzer. 4. A recursive back reference by name within a group that had the same name as another group caused a buffer overflow. For example: /(?J)(?'d'(?'d'\g{d}))/. This bug was discovered by the LLVM fuzzer. 5. A forward reference by name to a group whose number is the same as the current group, for example in this pattern: /(?|(\k'Pm')|(?'Pm'))/, caused a buffer overflow at compile time. This bug was discovered by the LLVM fuzzer. 6. A lookbehind assertion within a set of mutually recursive subpatterns could provoke a buffer overflow. This bug was discovered by the LLVM fuzzer. 7. Another buffer overflow bug involved duplicate named groups with a reference between their definition, with a group that reset capture numbers, for example: /(?J:(?|(?'R')(\k'R')|((?'R'))))/. This has been fixed by always allowing for more memory, even if not needed. (A proper fix is implemented in PCRE2, but it involves more refactoring.) 8. There was no check for integer overflow in subroutine calls such as (?123). 9. The table entry for \l in EBCDIC environments was incorrect, leading to its being treated as a literal 'l' instead of causing an error. 10. There was a buffer overflow if pcre_exec() was called with an ovector of size 1. This bug was found by american fuzzy lop. 11. If a non-capturing group containing a conditional group that could match an empty string was repeated, it was not identified as matching an empty string itself. For example: /^(?:(?(1)x|)+)+$()/. 12. In an EBCDIC environment, pcretest was mishandling the escape sequences \a and \e in test subject lines. 13. In an EBCDIC environment, \a in a pattern was converted to the ASCII instead of the EBCDIC value. 14. The handling of \c in an EBCDIC environment has been revised so that it is now compatible with the specification in Perl's perlebcdic page. 15. The EBCDIC character 0x41 is a non-breaking space, equivalent to 0xa0 in ASCII/Unicode. This has now been added to the list of characters that are recognized as white space in EBCDIC. 16. When PCRE was compiled without UCP support, the use of \p and \P gave an error (correctly) when used outside a class, but did not give an error within a class. 17. \h within a class was incorrectly compiled in EBCDIC environments. 18. A pattern with an unmatched closing parenthesis that contained a backward assertion which itself contained a forward reference caused buffer overflow. And example pattern is: /(?=di(?<=(?1))|(?=(.))))/. 19. JIT should return with error when the compiled pattern requires more stack space than the maximum. 20. A possessively repeated conditional group that could match an empty string, for example, /(?(R))*+/, was incorrectly compiled. 21. Fix infinite recursion in the JIT compiler when certain patterns such as /(?:|a|){100}x/ are analysed. 22. Some patterns with character classes involving [: and \\ were incorrectly compiled and could cause reading from uninitialized memory or an incorrect error diagnosis. 23. Pathological patterns containing many nested occurrences of [: caused pcre_compile() to run for a very long time. 24. A conditional group with only one branch has an implicit empty alternative branch and must therefore be treated as potentially matching an empty string. 25. If (?R was followed by - or + incorrect behaviour happened instead of a diagnostic. 26. Arrange to give up on finding the minimum matching length for overly complex patterns. 27. Similar to (4) above: in a pattern with duplicated named groups and an occurrence of (?| it is possible for an apparently non-recursive back reference to become recursive if a later named group with the relevant number is encountered. This could lead to a buffer overflow. Wen Guanxing from Venustech ADLAB discovered this bug. 28. If pcregrep was given the -q option with -c or -l, or when handling a binary file, it incorrectly wrote output to stdout. 29. The JIT compiler did not restore the control verb head in case of *THEN control verbs. This issue was found by Karl Skomski with a custom LLVM fuzzer. 30. Error messages for syntax errors following \g and \k were giving inaccurate offsets in the pattern. 31. Added a check for integer overflow in conditions (?(<digits>) and (?(R<digits>). This omission was discovered by Karl Skomski with the LLVM fuzzer. 32. Handling recursive references such as (?2) when the reference is to a group later in the pattern uses code that is very hacked about and error-prone. It has been re-written for PCRE2. Here in PCRE1, a check has been added to give an internal error if it is obvious that compiling has gone wrong. 33. The JIT compiler should not check repeats after a {0,1} repeat byte code. This issue was found by Karl Skomski with a custom LLVM fuzzer. 34. The JIT compiler should restore the control chain for empty possessive repeats. This issue was found by Karl Skomski with a custom LLVM fuzzer. 35. Match limit check added to JIT recursion. This issue was found by Karl Skomski with a custom LLVM fuzzer. 36. Yet another case similar to 27 above has been circumvented by an unconditional allocation of extra memory. This issue is fixed "properly" in PCRE2 by refactoring the way references are handled. Wen Guanxing from Venustech ADLAB discovered this bug. 37. Fix two assertion fails in JIT. These issues were found by Karl Skomski with a custom LLVM fuzzer. 38. Fixed a corner case of range optimization in JIT. 39. An incorrect error "overran compiling workspace" was given if there were exactly enough group forward references such that the last one extended into the workspace safety margin. The next one would have expanded the workspace. The test for overflow was not including the safety margin. 40. A match limit issue is fixed in JIT which was found by Karl Skomski with a custom LLVM fuzzer. 41. Remove the use of /dev/null in testdata/testinput2, because it doesn't work under Windows. (Why has it taken so long for anyone to notice?) 42. In a character class such as [\W\p{Any}] where both a negative-type escape ("not a word character") and a property escape were present, the property escape was being ignored. 43. Fix crash caused by very long (*MARK) or (*THEN) names. 44. A sequence such as [[:punct:]b] that is, a POSIX character class followed by a single ASCII character in a class item, was incorrectly compiled in UCP mode. The POSIX class got lost, but only if the single character followed it. 45. [:punct:] in UCP mode was matching some characters in the range 128-255 that should not have been matched. 46. If [:^ascii:] or [:^xdigit:] or [:^cntrl:] are present in a non-negated class, all characters with code points greater than 255 are in the class. When a Unicode property was also in the class (if PCRE_UCP is set, escapes such as \w are turned into Unicode properties), wide characters were not correctly handled, and could fail to match. Version 8.37 28-April-2015 -------------------------- 1. When an (*ACCEPT) is triggered inside capturing parentheses, it arranges for those parentheses to be closed with whatever has been captured so far. However, it was failing to mark any other groups between the hightest capture so far and the currrent group as "unset". Thus, the ovector for those groups contained whatever was previously there. An example is the pattern /(x)|((*ACCEPT))/ when matched against "abcd". 2. If an assertion condition was quantified with a minimum of zero (an odd thing to do, but it happened), SIGSEGV or other misbehaviour could occur. 3. If a pattern in pcretest input had the P (POSIX) modifier followed by an unrecognized modifier, a crash could occur. 4. An attempt to do global matching in pcretest with a zero-length ovector caused a crash. 5. Fixed a memory leak during matching that could occur for a subpattern subroutine call (recursive or otherwise) if the number of captured groups that had to be saved was greater than ten. 6. Catch a bad opcode during auto-possessification after compiling a bad UTF string with NO_UTF_CHECK. This is a tidyup, not a bug fix, as passing bad UTF with NO_UTF_CHECK is documented as having an undefined outcome. 7. A UTF pattern containing a "not" match of a non-ASCII character and a subroutine reference could loop at compile time. Example: /[^\xff]((?1))/. 8. When a pattern is compiled, it remembers the highest back reference so that when matching, if the ovector is too small, extra memory can be obtained to use instead. A conditional subpattern whose condition is a check on a capture having happened, such as, for example in the pattern /^(?:(a)|b)(?(1)A|B)/, is another kind of back reference, but it was not setting the highest backreference number. This mattered only if pcre_exec() was called with an ovector that was too small to hold the capture, and there was no other kind of back reference (a situation which is probably quite rare). The effect of the bug was that the condition was always treated as FALSE when the capture could not be consulted, leading to a incorrect behaviour by pcre_exec(). This bug has been fixed. 9. A reference to a duplicated named group (either a back reference or a test for being set in a conditional) that occurred in a part of the pattern where PCRE_DUPNAMES was not set caused the amount of memory needed for the pattern to be incorrectly calculated, leading to overwriting. 10. A mutually recursive set of back references such as (\2)(\1) caused a segfault at study time (while trying to find the minimum matching length). The infinite loop is now broken (with the minimum length unset, that is, zero). 11. If an assertion that was used as a condition was quantified with a minimum of zero, matching went wrong. In particular, if the whole group had unlimited repetition and could match an empty string, a segfault was likely. The pattern (?(?=0)?)+ is an example that caused this. Perl allows assertions to be quantified, but not if they are being used as conditions, so the above pattern is faulted by Perl. PCRE has now been changed so that it also rejects such patterns. 12. A possessive capturing group such as (a)*+ with a minimum repeat of zero failed to allow the zero-repeat case if pcre2_exec() was called with an ovector too small to capture the group. 13. Fixed two bugs in pcretest that were discovered by fuzzing and reported by Red Hat Product Security: (a) A crash if /K and /F were both set with the option to save the compiled pattern. (b) Another crash if the option to print captured substrings in a callout was combined with setting a null ovector, for example \O\C+ as a subject string. 14. A pattern such as "((?2){0,1999}())?", which has a group containing a forward reference repeated a large (but limited) number of times within a repeated outer group that has a zero minimum quantifier, caused incorrect code to be compiled, leading to the error "internal error: previously-checked referenced subpattern not found" when an incorrect memory address was read. This bug was reported as "heap overflow", discovered by Kai Lu of Fortinet's FortiGuard Labs and given the CVE number CVE-2015-2325. 23. A pattern such as "((?+1)(\1))/" containing a forward reference subroutine call within a group that also contained a recursive back reference caused incorrect code to be compiled. This bug was reported as "heap overflow", discovered by Kai Lu of Fortinet's FortiGuard Labs, and given the CVE number CVE-2015-2326. 24. Computing the size of the JIT read-only data in advance has been a source of various issues, and new ones are still appear unfortunately. To fix existing and future issues, size computation is eliminated from the code, and replaced by on-demand memory allocation. 25. A pattern such as /(?i)[A-`]/, where characters in the other case are adjacent to the end of the range, and the range contained characters with more than one other case, caused incorrect behaviour when compiled in UTF mode. In that example, the range a-j was left out of the class. 26. Fix JIT compilation of conditional blocks, which assertion is converted to (*FAIL). E.g: /(?(?!))/. 27. The pattern /(?(?!)^)/ caused references to random memory. This bug was discovered by the LLVM fuzzer. 28. The assertion (?!) is optimized to (*FAIL). This was not handled correctly when this assertion was used as a condition, for example (?(?!)a|b). In pcre2_match() it worked by luck; in pcre2_dfa_match() it gave an incorrect error about an unsupported item. 29. For some types of pattern, for example /Z*(|d*){216}/, the auto- possessification code could take exponential time to complete. A recursion depth limit of 1000 has been imposed to limit the resources used by this optimization. 30. A pattern such as /(*UTF)[\S\V\H]/, which contains a negated special class such as \S in non-UCP mode, explicit wide characters (> 255) can be ignored because \S ensures they are all in the class. The code for doing this was interacting badly with the code for computing the amount of space needed to compile the pattern, leading to a buffer overflow. This bug was discovered by the LLVM fuzzer. 31. A pattern such as /((?2)+)((?1))/ which has mutual recursion nested inside other kinds of group caused stack overflow at compile time. This bug was discovered by the LLVM fuzzer. 32. A pattern such as /(?1)(?#?'){8}(a)/ which had a parenthesized comment between a subroutine call and its quantifier was incorrectly compiled, leading to buffer overflow or other errors. This bug was discovered by the LLVM fuzzer. 33. The illegal pattern /(?(?<E>.*!.*)?)/ was not being diagnosed as missing an assertion after (?(. The code was failing to check the character after (?(?< for the ! or = that would indicate a lookbehind assertion. This bug was discovered by the LLVM fuzzer. 34. A pattern such as /X((?2)()*+){2}+/ which has a possessive quantifier with a fixed maximum following a group that contains a subroutine reference was incorrectly compiled and could trigger buffer overflow. This bug was discovered by the LLVM fuzzer. 35. A mutual recursion within a lookbehind assertion such as (?<=((?2))((?1))) caused a stack overflow instead of the diagnosis of a non-fixed length lookbehind assertion. This bug was discovered by the LLVM fuzzer. 36. The use of \K in a positive lookbehind assertion in a non-anchored pattern (e.g. /(?<=\Ka)/) could make pcregrep loop. 37. There was a similar problem to 36 in pcretest for global matches. 38. If a greedy quantified \X was preceded by \C in UTF mode (e.g. \C\X*), and a subsequent item in the pattern caused a non-match, backtracking over the repeated \X did not stop, but carried on past the start of the subject, causing reference to random memory and/or a segfault. There were also some other cases where backtracking after \C could crash. This set of bugs was discovered by the LLVM fuzzer. 39. The function for finding the minimum length of a matching string could take a very long time if mutual recursion was present many times in a pattern, for example, /((?2){73}(?2))((?1))/. A better mutual recursion detection method has been implemented. This infelicity was discovered by the LLVM fuzzer. 40. Static linking against the PCRE library using the pkg-config module was failing on missing pthread symbols. Version 8.36 26-September-2014 ------------------------------ 1. Got rid of some compiler warnings in the C++ modules that were shown up by -Wmissing-field-initializers and -Wunused-parameter. 2. The tests for quantifiers being too big (greater than 65535) were being applied after reading the number, and stupidly assuming that integer overflow would give a negative number. The tests are now applied as the numbers are read. 3. Tidy code in pcre_exec.c where two branches that used to be different are now the same. 4. The JIT compiler did not generate match limit checks for certain bracketed expressions with quantifiers. This may lead to exponential backtracking, instead of returning with PCRE_ERROR_MATCHLIMIT. This issue should be resolved now. 5. Fixed an issue, which occures when nested alternatives are optimized with table jumps. 6. Inserted two casts and changed some ints to size_t in the light of some reported 64-bit compiler warnings (Bugzilla 1477). 7. Fixed a bug concerned with zero-minimum possessive groups that could match an empty string, which sometimes were behaving incorrectly in the interpreter (though correctly in the JIT matcher). This pcretest input is an example: '\A(?:[^"]++|"(?:[^"]*+|"")*+")++' NON QUOTED "QUOT""ED" AFTER "NOT MATCHED the interpreter was reporting a match of 'NON QUOTED ' only, whereas the JIT matcher and Perl both matched 'NON QUOTED "QUOT""ED" AFTER '. The test for an empty string was breaking the inner loop and carrying on at a lower level, when possessive repeated groups should always return to a higher level as they have no backtrack points in them. The empty string test now occurs at the outer level. 8. Fixed a bug that was incorrectly auto-possessifying \w+ in the pattern ^\w+(?>\s*)(?<=\w) which caused it not to match "test test". 9. Give a compile-time error for \o{} (as Perl does) and for \x{} (which Perl doesn't). 10. Change 8.34/15 introduced a bug that caused the amount of memory needed to hold a pattern to be incorrectly computed (too small) when there were named back references to duplicated names. This could cause "internal error: code overflow" or "double free or corruption" or other memory handling errors. 11. When named subpatterns had the same prefixes, back references could be confused. For example, in this pattern: /(?P<Name>a)?(?P<Name2>b)?(?(<Name>)c|d)*l/ the reference to 'Name' was incorrectly treated as a reference to a duplicate name. 12. A pattern such as /^s?c/mi8 where the optional character has more than one "other case" was incorrectly compiled such that it would only try to match starting at "c". 13. When a pattern starting with \s was studied, VT was not included in the list of possible starting characters; this should have been part of the 8.34/18 patch. 14. If a character class started [\Qx]... where x is any character, the class was incorrectly terminated at the ]. 15. If a pattern that started with a caseless match for a character with more than one "other case" was studied, PCRE did not set up the starting code unit bit map for the list of possible characters. Now it does. This is an optimization improvement, not a bug fix. 16. The Unicode data tables have been updated to Unicode 7.0.0. 17. Fixed a number of memory leaks in pcregrep. 18. Avoid a compiler warning (from some compilers) for a function call with a cast that removes "const" from an lvalue by using an intermediate variable (to which the compiler does not object). 19. Incorrect code was compiled if a group that contained an internal recursive back reference was optional (had quantifier with a minimum of zero). This example compiled incorrect code: /(((a\2)|(a*)\g<-1>))*/ and other examples caused segmentation faults because of stack overflows at compile time. 20. A pattern such as /((?(R)a|(?1)))+/, which contains a recursion within a group that is quantified with an indefinite repeat, caused a compile-time loop which used up all the system stack and provoked a segmentation fault. This was not the same bug as 19 above. 21. Add PCRECPP_EXP_DECL declaration to operator<< in pcre_stringpiece.h. Patch by Mike Frysinger. 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 threshold (e.g: 256). The only limitation is that the value must be bigger than the threshold as well. This function is useful when the characters above the threshold 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 Makefile.am (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 configure.ac 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 config-cmake.h.in; 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 perltest.pl 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 autogen.sh and configure.ac to lose warnings given by automake 1.12 and later. 8. Fix two buffer over read issues in 16 and 32 bit modes. Affects JIT only. 9. Optimizing fast_forward_start_bits in JIT. 10. Adding support for callouts in JIT, and fixing some issues revealed during this work. Namely: (a) Unoptimized capturing brackets incorrectly reset on backtrack. (b) Minimum length was not checked before the matching is started. 11. The value of capture_last that is passed to callouts was incorrect in some cases when there was a capture on one path that was subsequently abandoned after a backtrack. Also, the capture_last value is now reset after a recursion, since all captures are also reset in this case. 12. The interpreter no longer returns the "too many substrings" error in the case when an overflowing capture is in a branch that is subsequently abandoned after a backtrack. 13. In the pathological case when an offset vector of size 2 is used, pcretest now prints out the matched string after a yield of 0 or 1. 14. Inlining subpatterns in recursions, when certain conditions are fulfilled. Only supported by the JIT compiler at the moment. 15. JIT compiler now supports 32 bit Macs thanks to Lawrence Velazquez. 16. Partial matches now set offsets[2] to the "bumpalong" value, that is, the offset of the starting point of the matching process, provided the offsets vector is large enough. 17. The \A escape now records a lookbehind value of 1, though its execution does not actually inspect the previous character. This is to ensure that, in partial multi-segment matching, at least one character from the old segment is retained when a new segment is processed. Otherwise, if there are no lookbehinds in the pattern, \A might match incorrectly at the start of a new segment. 18. Added some #ifdef __VMS code into pcretest.c to help VMS implementations. 19. Redefined some pcre_uchar variables in pcre_exec.c as pcre_uint32; this gives some modest performance improvement in 8-bit mode. 20. Added the PCRE-specific property \p{Xuc} for matching characters that can be expressed in certain programming languages using Universal Character Names. 21. Unicode validation has been updated in the light of Unicode Corrigendum #9, which points out that "non characters" are not "characters that may not appear in Unicode strings" but rather "characters that are reserved for internal use and have only local meaning". 22. When a pattern was compiled with automatic callouts (PCRE_AUTO_CALLOUT) and there was a conditional group that depended on an assertion, if the assertion was false, the callout that immediately followed the alternation in the condition was skipped when pcre_exec() was used for matching. 23. Allow an explicit callout to be inserted before an assertion that is the condition for a conditional group, for compatibility with automatic callouts, which always insert a callout at this point. 24. In 8.31, (*COMMIT) was confined to within a recursive subpattern. Perl also confines (*SKIP) and (*PRUNE) in the same way, and this has now been done. 25. (*PRUNE) is now supported by the JIT compiler. 26. Fix infinite loop when /(?<=(*SKIP)ac)a/ is matched against aa. 27. Fix the case where there are two or more SKIPs with arguments that may be ignored. 28. (*SKIP) is now supported by the JIT compiler. 29. (*THEN) is now supported by the JIT compiler. 30. Update RunTest with additional test selector options. 31. The way PCRE handles backtracking verbs has been changed in two ways. (1) Previously, in something like (*COMMIT)(*SKIP), COMMIT would override SKIP. Now, PCRE acts on whichever backtracking verb is reached first by backtracking. In some cases this makes it more Perl-compatible, but Perl's rather obscure rules do not always do the same thing. (2) Previously, backtracking verbs were confined within assertions. This is no longer the case for positive assertions, except for (*ACCEPT). Again, this sometimes improves Perl compatibility, and sometimes does not. 32. A number of tests that were in test 2 because Perl did things differently have been moved to test 1, because either Perl or PCRE has changed, and these tests are now compatible. 32. Backtracking control verbs are now handled in the same way in JIT and interpreter. 33. An opening parenthesis in a MARK/PRUNE/SKIP/THEN name in a pattern that contained a forward subroutine reference caused a compile error. 34. Auto-detect and optimize limited repetitions in JIT. 35. Implement PCRE_NEVER_UTF to lock out the use of UTF, in particular, blocking (*UTF) etc. 36. In the interpreter, maximizing pattern repetitions for characters and character types now use tail recursion, which reduces stack usage. 37. The value of the max lookbehind was not correctly preserved if a compiled and saved regex was reloaded on a host of different endianness. 38. Implemented (*LIMIT_MATCH) and (*LIMIT_RECURSION). As part of the extension of the compiled pattern block, expand the flags field from 16 to 32 bits because it was almost full. 39. Try madvise first before posix_madvise. 40. Change 7 for PCRE 7.9 made it impossible for pcregrep to find empty lines with a pattern such as ^$. It has taken 4 years for anybody to notice! The original change locked out all matches of empty strings. This has been changed so that one match of an empty string per line is recognized. Subsequent searches on the same line (for colouring or for --only-matching, for example) do not recognize empty strings. 41. Applied a user patch to fix a number of spelling mistakes in comments. 42. Data lines longer than 65536 caused pcretest to crash. 43. Clarified the data type for length and startoffset arguments for pcre_exec and pcre_dfa_exec in the function-specific man pages, where they were explicitly stated to be in bytes, never having been updated. I also added some clarification to the pcreapi man page. 44. A call to pcre_dfa_exec() with an output vector size less than 2 caused a segmentation fault. Version 8.32 30-November-2012 ----------------------------- 1. Improved JIT compiler optimizations for first character search and single character iterators. 2. Supporting IBM XL C compilers for PPC architectures in the JIT compiler. Patch by Daniel Richard G. 3. Single character iterator optimizations in the JIT compiler. 4. Improved JIT compiler optimizations for character ranges. 5. Rename the "leave" variable names to "quit" to improve WinCE compatibility. Reported by Giuseppe D'Angelo. 6. The PCRE_STARTLINE bit, indicating that a match can occur only at the start of a line, was being set incorrectly in cases where .* appeared inside atomic brackets at the start of a pattern, or where there was a subsequent *PRUNE or *SKIP. 7. Improved instruction cache flush for POWER/PowerPC. Patch by Daniel Richard G. 8. Fixed a number of issues in pcregrep, making it more compatible with GNU grep: (a) There is now no limit to the number of patterns to be matched. (b) An error is given if a pattern is too long. (c) Multiple uses of --exclude, --exclude-dir, --include, and --include-dir are now supported. (d) --exclude-from and --include-from (multiple use) have been added. (e) Exclusions and inclusions now apply to all files and directories, not just to those obtained from scanning a directory recursively. (f) Multiple uses of -f and --file-list are now supported. (g) In a Windows environment, the default for -d has been changed from "read" (the GNU grep default) to "skip", because otherwise the presence of a directory in the file list provokes an error. (h) The documentation has been revised and clarified in places. 9. Improve the matching speed of capturing brackets. 10. Changed the meaning of \X so that it now matches a Unicode extended grapheme cluster. 11. Patch by Daniel Richard G to the autoconf files to add a macro for sorting out POSIX threads when JIT support is configured. 12. Added support for PCRE_STUDY_EXTRA_NEEDED. 13. In the POSIX wrapper regcomp() function, setting re_nsub field in the preg structure could go wrong in environments where size_t is not the same size as int. 14. Applied user-supplied patch to pcrecpp.cc to allow PCRE_NO_UTF8_CHECK to be set. 15. The EBCDIC support had decayed; later updates to the code had included explicit references to (e.g.) \x0a instead of CHAR_LF. There has been a general tidy up of EBCDIC-related issues, and the documentation was also not quite right. There is now a test that can be run on ASCII systems to check some of the EBCDIC-related things (but is it not a full test). 16. The new PCRE_STUDY_EXTRA_NEEDED option is now used by pcregrep, resulting in a small tidy to the code. 17. Fix JIT tests when UTF is disabled and both 8 and 16 bit mode are enabled. 18. If the --only-matching (-o) option in pcregrep is specified multiple times, each one causes appropriate output. For example, -o1 -o2 outputs the substrings matched by the 1st and 2nd capturing parentheses. A separating string can be specified by --om-separator (default empty). 19. Improving the first n character searches. 20. Turn case lists for horizontal and vertical white space into macros so that they are defined only once. 21. This set of changes together give more compatible Unicode case-folding behaviour for characters that have more than one other case when UCP support is available. (a) The Unicode property table now has offsets into a new table of sets of three or more characters that are case-equivalent. The MultiStage2.py script that generates these tables (the pcre_ucd.c file) now scans CaseFolding.txt instead of UnicodeData.txt for character case information. (b) The code for adding characters or ranges of characters to a character class has been abstracted into a generalized function that also handles case-independence. In UTF-mode with UCP support, this uses the new data to handle characters with more than one other case. (c) A bug that is fixed as a result of (b) is that codepoints less than 256 whose other case is greater than 256 are now correctly matched caselessly. Previously, the high codepoint matched the low one, but not vice versa. (d) The processing of \h, \H, \v, and \ in character classes now makes use of the new class addition function, using character lists defined as macros alongside the case definitions of 20 above. (e) Caseless back references now work with characters that have more than one other case. (f) General caseless matching of characters with more than one other case is supported. 22. Unicode character properties were updated from Unicode 6.2.0 23. Improved CMake support under Windows. Patch by Daniel Richard G. 24. Add support for 32-bit character strings, and UTF-32 25. Major JIT compiler update (code refactoring and bugfixing). Experimental Sparc 32 support is added. 26. Applied a modified version of Daniel Richard G's patch to create pcre.h.generic and config.h.generic by "make" instead of in the PrepareRelease script. 27. Added a definition for CHAR_NULL (helpful for the z/OS port), and use it in pcre_compile.c when checking for a zero character. 28. Introducing a native interface for JIT. Through this interface, the compiled machine code can be directly executed. The purpose of this interface is to provide fast pattern matching, so several sanity checks are not performed. However, feature tests are still performed. The new interface provides 1.4x speedup compared to the old one. 29. If pcre_exec() or pcre_dfa_exec() was called with a negative value for the subject string length, the error given was PCRE_ERROR_BADOFFSET, which was confusing. There is now a new error PCRE_ERROR_BADLENGTH for this case. 30. In 8-bit UTF-8 mode, pcretest failed to give an error for data codepoints greater than 0x7fffffff (which cannot be represented in UTF-8, even under the "old" RFC 2279). Instead, it ended up passing a negative length to pcre_exec(). 31. Add support for GCC's visibility feature to hide internal functions. 32. Running "pcretest -C pcre8" or "pcretest -C pcre16" gave a spurious error "unknown -C option" after outputting 0 or 1. 33. There is now support for generating a code coverage report for the test suite in environments where gcc is the compiler and lcov is installed. This is mainly for the benefit of the developers. 34. If PCRE is built with --enable-valgrind, certain memory regions are marked unaddressable using valgrind annotations, allowing valgrind to detect invalid memory accesses. This is mainly for the benefit of the developers. 25. (*UTF) can now be used to start a pattern in any of the three libraries. 26. Give configure error if --enable-cpp but no C++ compiler found. Version 8.31 06-July-2012 ------------------------- 1. Fixing a wrong JIT test case and some compiler warnings. 2. Removed a bashism from the RunTest script. 3. Add a cast to pcre_exec.c to fix the warning "unary minus operator applied to unsigned type, result still unsigned" that was given by an MS compiler on encountering the code "-sizeof(xxx)". 4. Partial matching support is added to the JIT compiler. 5. Fixed several bugs concerned with partial matching of items that consist of more than one character: (a) /^(..)\1/ did not partially match "aba" because checking references was done on an "all or nothing" basis. This also applied to repeated references. (b) \R did not give a hard partial match if \r was found at the end of the subject. (c) \X did not give a hard partial match after matching one or more characters at the end of the subject. (d) When newline was set to CRLF, a pattern such as /a$/ did not recognize a partial match for the string "\r". (e) When newline was set to CRLF, the metacharacter "." did not recognize a partial match for a CR character at the end of the subject string. 6. If JIT is requested using /S++ or -s++ (instead of just /S+ or -s+) when running pcretest, the text "(JIT)" added to the output whenever JIT is actually used to run the match. 7. Individual JIT compile options can be set in pcretest by following -s+[+] or /S+[+] with a digit between 1 and 7. 8. OP_NOT now supports any UTF character not just single-byte ones. 9. (*MARK) control verb is now supported by the JIT compiler. 10. The command "./RunTest list" lists the available tests without actually running any of them. (Because I keep forgetting what they all are.) 11. Add PCRE_INFO_MAXLOOKBEHIND. 12. Applied a (slightly modified) user-supplied patch that improves performance when the heap is used for recursion (compiled with --disable-stack-for- recursion). Instead of malloc and free for each heap frame each time a logical recursion happens, frames are retained on a chain and re-used where possible. This sometimes gives as much as 30% improvement. 13. As documented, (*COMMIT) is now confined to within a recursive subpattern call. 14. As documented, (*COMMIT) is now confined to within a positive assertion. 15. It is now possible to link pcretest with libedit as an alternative to libreadline. 16. (*COMMIT) control verb is now supported by the JIT compiler. 17. The Unicode data tables have been updated to Unicode 6.1.0. 18. Added --file-list option to pcregrep. 19. Added binary file support to pcregrep, including the -a, --binary-files, -I, and --text options. 20. The madvise function is renamed for posix_madvise for QNX compatibility reasons. Fixed by Giuseppe D'Angelo. 21. Fixed a bug for backward assertions with REVERSE 0 in the JIT compiler. 22. Changed the option for creating symbolic links for 16-bit man pages from -s to -sf so that re-installing does not cause issues. 23. Support PCRE_NO_START_OPTIMIZE in JIT as (*MARK) support requires it. 24. Fixed a very old bug in pcretest that caused errors with restarted DFA matches in certain environments (the workspace was not being correctly retained). Also added to pcre_dfa_exec() a simple plausibility check on some of the workspace data at the beginning of a restart. 25. \s*\R was auto-possessifying the \s* when it should not, whereas \S*\R was not doing so when it should - probably a typo introduced by SVN 528 (change 8.10/14). 26. When PCRE_UCP was not set, \w+\x{c4} was incorrectly auto-possessifying the \w+ when the character tables indicated that \x{c4} was a word character. There were several related cases, all because the tests for doing a table lookup were testing for characters less than 127 instead of 255. 27. If a pattern contains capturing parentheses that are not used in a match, their slots in the ovector are set to -1. For those that are higher than any matched groups, this happens at the end of processing. In the case when there were back references that the ovector was too small to contain (causing temporary malloc'd memory to be used during matching), and the highest capturing number was not used, memory off the end of the ovector was incorrectly being set to -1. (It was using the size of the temporary memory instead of the true size.) 28. To catch bugs like 27 using valgrind, when pcretest is asked to specify an ovector size, it uses memory at the end of the block that it has got. 29. Check for an overlong MARK name and give an error at compile time. The limit is 255 for the 8-bit library and 65535 for the 16-bit library. 30. JIT compiler update. 31. JIT is now supported on jailbroken iOS devices. Thanks for Ruiger Rill for the patch. 32. Put spaces around SLJIT_PRINT_D in the JIT compiler. Required by CXX11. 33. Variable renamings in the PCRE-JIT compiler. No functionality change. 34. Fixed typos in pcregrep: in two places there was SUPPORT_LIBZ2 instead of SUPPORT_LIBBZ2. This caused a build problem when bzip2 but not gzip (zlib) was enabled. 35. Improve JIT code generation for greedy plus quantifier. 36. When /((?:a?)*)*c/ or /((?>a?)*)*c/ was matched against "aac", it set group 1 to "aa" instead of to an empty string. The bug affected repeated groups that could potentially match an empty string. 37. Optimizing single character iterators in JIT. 38. Wide characters specified with \uxxxx in JavaScript mode are now subject to the same checks as \x{...} characters in non-JavaScript mode. Specifically, codepoints that are too big for the mode are faulted, and in a UTF mode, disallowed codepoints are also faulted. 39. If PCRE was compiled with UTF support, in three places in the DFA matcher there was code that should only have been obeyed in UTF mode, but was being obeyed unconditionally. In 8-bit mode this could cause incorrect processing when bytes with values greater than 127 were present. In 16-bit mode the bug would be provoked by values in the range 0xfc00 to 0xdc00. In both cases the values are those that cannot be the first data item in a UTF character. The three items that might have provoked this were recursions, possessively repeated groups, and atomic groups. 40. Ensure that libpcre is explicitly listed in the link commands for pcretest and pcregrep, because some OS require shared objects to be explicitly passed to ld, causing the link step to fail if they are not. 41. There were two incorrect #ifdefs in pcre_study.c, meaning that, in 16-bit mode, patterns that started with \h* or \R* might be incorrectly matched. Version 8.30 04-February-2012 ----------------------------- 1. Renamed "isnumber" as "is_a_number" because in some Mac environments this name is defined in ctype.h. 2. Fixed a bug in fixed-length calculation for lookbehinds that would show up only in quite long subpatterns. 3. Removed the function pcre_info(), which has been obsolete and deprecated since it was replaced by pcre_fullinfo() in February 2000. 4. For a non-anchored pattern, if (*SKIP) was given with a name that did not match a (*MARK), and the match failed at the start of the subject, a reference to memory before the start of the subject could occur. This bug was introduced by fix 17 of release 8.21. 5. A reference to an unset group with zero minimum repetition was giving totally wrong answers (in non-JavaScript-compatibility mode). For example, /(another)?(\1?)test/ matched against "hello world test". This bug was introduced in release 8.13. 6. Add support for 16-bit character strings (a large amount of work involving many changes and refactorings). 7. RunGrepTest failed on msys because \r\n was replaced by whitespace when the command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken from a file. 8. Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size rounding is not applied in this particular case). 9. The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected if they appear, or are escaped, in patterns. 10. Get rid of a number of -Wunused-but-set-variable warnings. 11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all. Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern also returns the mark "x". This bug applied to capturing parentheses, non-capturing parentheses, and atomic parentheses. It also applied to some assertions. 12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version information out of configure.ac instead of relying on pcre.h.generic, which is not stored in the repository. 13. Applied Dmitry V. Levin's patch for a more portable method for linking with -lreadline. 14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C. 15. Applied Graycode's patch to put the top-level frame on the stack rather than the heap when not using the stack for recursion. This gives a performance improvement in many cases when recursion is not deep. 16. Experimental code added to "pcretest -C" to output the stack frame size. Version 8.21 12-Dec-2011 ------------------------ 1. Updating the JIT compiler. 2. JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases are added as well. 3. Fix cache-flush issue on PowerPC (It is still an experimental JIT port). PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before calling _pcre_jit_exec. Some extra comments are added. 4. (*MARK) settings inside atomic groups that do not contain any capturing parentheses, for example, (?>a(*:m)), were not being passed out. This bug was introduced by change 18 for 8.20. 5. Supporting of \x, \U and \u in JavaScript compatibility mode based on the ECMA-262 standard. 6. Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were erroneously being rejected as "not fixed length" if PCRE_CASELESS was set. This bug was probably introduced by change 9 of 8.13. 7. While fixing 6 above, I noticed that a number of other items were being incorrectly rejected as "not fixed length". This arose partly because newer opcodes had not been added to the fixed-length checking code. I have (a) corrected the bug and added tests for these items, and (b) arranged for an error to occur if an unknown opcode is encountered while checking for fixed length instead of just assuming "not fixed length". The items that were rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP), (*THEN), \h, \H, \v, \V, and single character negative classes with fixed repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS. 8. A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was being incorrectly compiled and would have given unpredicatble results. 9. A possessively repeated subpattern with minimum repeat count greater than one behaved incorrectly. For example, (A){2,}+ behaved as if it was (A)(A)++ which meant that, after a subsequent mismatch, backtracking into the first (A) could occur when it should not. 10. Add a cast and remove a redundant test from the code. 11. JIT should use pcre_malloc/pcre_free for allocation. 12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems best practice nowadays, and helps with cross-compiling. (If the exec_prefix is anything other than /usr, -L is still shown). 13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching. 14. Perl does not support \N without a following name in a [] class; PCRE now also gives an error. 15. If a forward reference was repeated with an upper limit of around 2000, it caused the error "internal error: overran compiling workspace". The maximum number of forward references (including repeats) was limited by the internal workspace, and dependent on the LINK_SIZE. The code has been rewritten so that the workspace expands (via pcre_malloc) if necessary, and the default depends on LINK_SIZE. There is a new upper limit (for safety) of around 200,000 forward references. While doing this, I also speeded up the filling in of repeated forward references. 16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was incorrectly expecting the subject to contain another "a" after the start. 17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier in the match, the SKIP should be ignored. This was not happening; instead the SKIP was being treated as NOMATCH. For patterns such as /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never tested. 18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is now much more compatible with Perl, in particular in cases where the result is a non-match for a non-anchored pattern. For example, if /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name "m", where previously it did not return a name. A side effect of this change is that for partial matches, the last encountered mark name is returned, as for non matches. A number of tests that were previously not Perl-compatible have been moved into the Perl-compatible test files. The refactoring has had the pleasing side effect of removing one argument from the match() function, thus reducing its stack requirements. 19. If the /S+ option was used in pcretest to study a pattern using JIT, subsequent uses of /S (without +) incorrectly behaved like /S+. 21. Retrieve executable code size support for the JIT compiler and fixing some warnings. 22. A caseless match of a UTF-8 character whose other case uses fewer bytes did not work when the shorter character appeared right at the end of the subject string. 23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit systems. 24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also output it when the /M option is used in pcretest. 25. The CheckMan script was not being included in the distribution. Also, added an explicit "perl" to run Perl scripts from the PrepareRelease script because this is reportedly needed in Windows. 26. If study data was being save in a file and studying had not found a set of "starts with" bytes for the pattern, the data written to the file (though never used) was taken from uninitialized memory and so caused valgrind to complain. 27. Updated RunTest.bat as provided by Sheri Pierce. 28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c. 29. Computation of memory usage for the table of capturing group names was giving an unnecessarily large value. Version 8.20 21-Oct-2011 ------------------------ 1. Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had a POSIX class. After further experiments with Perl, which convinced me that Perl has bugs and confusions, a closing square bracket is no longer allowed in a POSIX name. This bug also affected patterns with classes that started with full stops. 2. If a pattern such as /(a)b|ac/ is matched against "ac", there is no captured substring, but while checking the failing first alternative, substring 1 is temporarily captured. If the output vector supplied to pcre_exec() was not big enough for this capture, the yield of the function was still zero ("insufficient space for captured substrings"). This cannot be totally fixed without adding another stack variable, which seems a lot of expense for a edge case. However, I have improved the situation in cases such as /(a)(b)x|abc/ matched against "abc", where the return code indicates that fewer than the maximum number of slots in the ovector have been set. 3. Related to (2) above: when there are more back references in a pattern than slots in the output vector, pcre_exec() uses temporary memory during matching, and copies in the captures as far as possible afterwards. It was using the entire output vector, but this conflicts with the specification that only 2/3 is used for passing back captured substrings. Now it uses only the first 2/3, for compatibility. This is, of course, another edge case. 4. Zoltan Herczeg's just-in-time compiler support has been integrated into the main code base, and can be used by building with --enable-jit. When this is done, pcregrep automatically uses it unless --disable-pcregrep-jit or the runtime --no-jit option is given. 5. When the number of matches in a pcre_dfa_exec() run exactly filled the ovector, the return from the function was zero, implying that there were other matches that did not fit. The correct "exactly full" value is now returned. 6. If a subpattern that was called recursively or as a subroutine contained (*PRUNE) or any other control that caused it to give a non-standard return, invalid errors such as "Error -26 (nested recursion at the same subject position)" or even infinite loops could occur. 7. If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped computing the minimum length on reaching *ACCEPT, and so ended up with the wrong value of 1 rather than 0. Further investigation indicates that computing a minimum subject length in the presence of *ACCEPT is difficult (think back references, subroutine calls), and so I have changed the code so that no minimum is registered for a pattern that contains *ACCEPT. 8. If (*THEN) was present in the first (true) branch of a conditional group, it was not handled as intended. [But see 16 below.] 9. Replaced RunTest.bat and CMakeLists.txt with improved versions provided by Sheri Pierce. 10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that the first byte in a match must be "a". 11. Change 17 for 8.13 increased the recursion depth for patterns like /a(?:.)*?a/ drastically. I've improved things by remembering whether a pattern contains any instances of (*THEN). If it does not, the old optimizations are restored. It would be nice to do this on a per-group basis, but at the moment that is not feasible. 12. In some environments, the output of pcretest -C is CRLF terminated. This broke RunTest's code that checks for the link size. A single white space character after the value is now allowed for. 13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french". For "fr", it uses the Windows-specific input and output files. 14. If (*THEN) appeared in a group that was called recursively or as a subroutine, it did not work as intended. [But see next item.] 15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex pattern fragments (but not containing any | characters). If A and B are matched, but there is a failure in C so that it backtracks to (*THEN), PCRE was behaving differently to Perl. PCRE backtracked into A, but Perl goes to D. In other words, Perl considers parentheses that do not contain any | characters to be part of a surrounding alternative, whereas PCRE was treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles differently. PCRE now behaves in the same way as Perl, except in the case of subroutine/recursion calls such as (?1) which have in any case always been different (but PCRE had them first :-). 16. Related to 15 above: Perl does not treat the | in a conditional group as creating alternatives. Such a group is treated in the same way as an ordinary group without any | characters when processing (*THEN). PCRE has been changed to match Perl's behaviour. 17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the RunGrepTest script failed. 18. Change 22 for version 13 caused atomic groups to use more stack. This is inevitable for groups that contain captures, but it can lead to a lot of stack use in large patterns. The old behaviour has been restored for atomic groups that do not contain any capturing parentheses. 19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not suppress the check for a minimum subject length at run time. (If it was given to pcre_exec() or pcre_dfa_exec() it did work.) 20. Fixed an ASCII-dependent infelicity in pcretest that would have made it fail to work when decoding hex characters in data strings in EBCDIC environments. 21. It appears that in at least one Mac OS environment, the isxdigit() function is implemented as a macro that evaluates to its argument more than once, contravening the C 90 Standard (I haven't checked a later standard). There was an instance in pcretest which caused it to go wrong when processing \x{...} escapes in subject strings. The has been rewritten to avoid using things like p++ in the argument of isxdigit(). Version 8.13 16-Aug-2011 ------------------------ 1. The Unicode data tables have been updated to Unicode 6.0.0. 2. Two minor typos in pcre_internal.h have been fixed. 3. Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr() in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2). 4. There were a number of related bugs in the code for matching backrefences caselessly in UTF-8 mode when codes for the characters concerned were different numbers of bytes. For example, U+023A and U+2C65 are an upper and lower case pair, using 2 and 3 bytes, respectively. The main bugs were: (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a 2-byte code at the end of the subject (it thought there wasn't enough data left). 5. Comprehensive information about what went wrong is now returned by pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long as the output vector has at least 2 elements. The offset of the start of the failing character and a reason code are placed in the vector. 6. When the UTF-8 string check fails for pcre_compile(), the offset that is now returned is for the first byte of the failing character, instead of the last byte inspected. This is an incompatible change, but I hope it is small enough not to be a problem. It makes the returned offset consistent with pcre_exec() and pcre_dfa_exec(). 7. pcretest now gives a text phrase as well as the error number when pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check failure, the offset and reason code are output. 8. When \R was used with a maximizing quantifier it failed to skip backwards over a \r\n pair if the subsequent match failed. Instead, it just skipped back over a single character (\n). This seems wrong (because it treated the two characters as a single entity when going forwards), conflicts with the documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the behaviour of \R* different to (\R)*, which also seems wrong. The behaviour has been changed. 9. Some internal refactoring has changed the processing so that the handling of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile time (the PCRE_DOTALL option was changed this way some time ago: version 7.7 change 16). This has made it possible to abolish the OP_OPT op code, which was always a bit of a fudge. It also means that there is one less argument for the match() function, which reduces its stack requirements slightly. This change also fixes an incompatibility with Perl: the pattern (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match. 10. More internal refactoring has drastically reduced the number of recursive calls to match() for possessively repeated groups such as (abc)++ when using pcre_exec(). 11. While implementing 10, a number of bugs in the handling of groups were discovered and fixed: (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind). (a|)*(?1) gave a compile-time internal error. ((a|)+)+ did not notice that the outer group could match an empty string. (^a|^)+ was not marked as anchored. (.*a|.*)+ was not marked as matching at start or after a newline. 12. Yet more internal refactoring has removed another argument from the match() function. Special calls to this function are now indicated by setting a value in a variable in the "match data" data block. 13. Be more explicit in pcre_study() instead of relying on "default" for opcodes that mean there is no starting character; this means that when new ones are added and accidentally left out of pcre_study(), testing should pick them up. 14. The -s option of pcretest has been documented for ages as being an old synonym of -m (show memory usage). I have changed it to mean "force study for every regex", that is, assume /S for every regex. This is similar to -i and -d etc. It's slightly incompatible, but I'm hoping nobody is still using it. It makes it easier to run collections of tests with and without study enabled, and thereby test pcre_study() more easily. All the standard tests are now run with and without -s (but some patterns can be marked as "never study" - see 20 below). 15. When (*ACCEPT) was used in a subpattern that was called recursively, the restoration of the capturing data to the outer values was not happening correctly. 16. If a recursively called subpattern ended with (*ACCEPT) and matched an empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole pattern had matched an empty string, and so incorrectly returned a no match. 17. There was optimizing code for the last branch of non-capturing parentheses, and also for the obeyed branch of a conditional subexpression, which used tail recursion to cut down on stack usage. Unfortunately, now that there is the possibility of (*THEN) occurring in these branches, tail recursion is no longer possible because the return has to be checked for (*THEN). These two optimizations have therefore been removed. [But see 8.20/11 above.] 18. If a pattern containing \R was studied, it was assumed that \R always matched two bytes, thus causing the minimum subject length to be incorrectly computed because \R can also match just one byte. 19. If a pattern containing (*ACCEPT) was studied, the minimum subject length was incorrectly computed. 20. If /S is present twice on a test pattern in pcretest input, it now *disables* studying, thereby overriding the use of -s on the command line (see 14 above). This is necessary for one or two tests to keep the output identical in both cases. 21. When (*ACCEPT) was used in an assertion that matched an empty string and PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion. 22. When an atomic group that contained a capturing parenthesis was successfully matched, but the branch in which it appeared failed, the capturing was not being forgotten if a higher numbered group was later captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing group 1 to "a", when in fact it should be unset. This applied to multi- branched capturing and non-capturing groups, repeated or not, and also to positive assertions (capturing in negative assertions does not happen in PCRE) and also to nested atomic groups. 23. Add the ++ qualifier feature to pcretest, to show the remainder of the subject after a captured substring, to make it easier to tell which of a number of identical substrings has been captured. 24. The way atomic groups are processed by pcre_exec() has been changed so that if they are repeated, backtracking one repetition now resets captured values correctly. For example, if ((?>(a+)b)+aabab) is matched against "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as "aaa". Previously, it would have been "a". As part of this code refactoring, the way recursive calls are handled has also been changed. 25. If an assertion condition captured any substrings, they were not passed back unless some other capturing happened later. For example, if (?(?=(a))a) was matched against "a", no capturing was returned. 26. When studying a pattern that contained subroutine calls or assertions, the code for finding the minimum length of a possible match was handling direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where group 1 called group 2 while simultaneously a separate group 2 called group 1). A stack overflow occurred in this case. I have fixed this by limiting the recursion depth to 10. 27. Updated RunTest.bat in the distribution to the version supplied by Tom Fortmann. This supports explicit test numbers on the command line, and has argument validation and error reporting. 28. An instance of \X with an unlimited repeat could fail if at any point the first character it looked at was a mark character. 29. Some minor code refactoring concerning Unicode properties and scripts should reduce the stack requirement of match() slightly. 30. Added the '=' option to pcretest to check the setting of unused capturing slots at the end of the pattern, which are documented as being -1, but are not included in the return count. 31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE compiled something random. Now it gives a compile-time error (as does Perl). 32. A *MARK encountered during the processing of a positive assertion is now recorded and passed back (compatible with Perl). 33. If --only-matching or --colour was set on a pcregrep call whose pattern had alternative anchored branches, the search for a second match in a line was done as if at the line start. Thus, for example, /^01|^02/ incorrectly matched the line "0102" twice. The same bug affected patterns that started with a backwards assertion. For example /\b01|\b02/ also matched "0102" twice. 34. Previously, PCRE did not allow quantification of assertions. However, Perl does, and because of capturing effects, quantifying parenthesized assertions may at times be useful. Quantifiers are now allowed for parenthesized assertions. 35. A minor code tidy in pcre_compile() when checking options for \R usage. 36. \g was being checked for fancy things in a character class, when it should just be a literal "g". 37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the appearance of a nested POSIX class supersedes an apparent external class. For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also, unescaped square brackets may also appear as part of class names. For example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves more like Perl. (But see 8.20/1 above.) 38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this was because it thought it was \N{name}, which is not supported). 39. Add minix to OS list not supporting the -S option in pcretest. 40. PCRE tries to detect cases of infinite recursion at compile time, but it cannot analyze patterns in sufficient detail to catch mutual recursions such as ((?1))((?2)). There is now a runtime test that gives an error if a subgroup is called recursively as a subpattern for a second time at the same position in the subject string. In previous releases this might have been caught by the recursion limit, or it might have run out of stack. 41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can happen only once. PCRE was, however incorrectly giving a compile time error "recursive call could loop indefinitely" because it cannot analyze the pattern in sufficient detail. The compile time test no longer happens when PCRE is compiling a conditional subpattern, but actual runaway loops are now caught at runtime (see 40 above). 42. It seems that Perl allows any characters other than a closing parenthesis to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE has been changed to be the same. 43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so as not to get warnings when autogen.sh is called. Also changed AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro). 44. To help people who use pcregrep to scan files containing exceedingly long lines, the following changes have been made: (a) The default value of the buffer size parameter has been increased from 8K to 20K. (The actual buffer used is three times this size.) (b) The default can be changed by ./configure --with-pcregrep-bufsize when PCRE is built. (c) A --buffer-size=n option has been added to pcregrep, to allow the size to be set at run time. (d) Numerical values in pcregrep options can be followed by K or M, for example --buffer-size=50K. (e) If a line being scanned overflows pcregrep's buffer, an error is now given and the return code is set to 2. 45. Add a pointer to the latest mark to the callout data block. 46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a partial match of an empty string instead of no match. This was specific to the use of ".". 47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a complete match instead of a partial match. This bug was dependent on both the PCRE_UTF8 and PCRE_DOTALL options being set. 48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the starting byte set, because \b was not being ignored. Version 8.12 15-Jan-2011 ------------------------ 1. Fixed some typos in the markup of the man pages, and wrote a script that checks for such things as part of the documentation building process. 2. On a big-endian 64-bit system, pcregrep did not correctly process the --match-limit and --recursion-limit options (added for 8.11). In particular, this made one of the standard tests fail. (The integer value went into the wrong half of a long int.) 3. If the --colour option was given to pcregrep with -v (invert match), it did strange things, either producing crazy output, or crashing. It should, of course, ignore a request for colour when reporting lines that do not match. 4. Another pcregrep bug caused similar problems if --colour was specified with -M (multiline) and the pattern match finished with a line ending. 5. In pcregrep, when a pattern that ended with a literal newline sequence was matched in multiline mode, the following line was shown as part of the match. This seems wrong, so I have changed it. 6. Another pcregrep bug in multiline mode, when --colour was specified, caused the check for further matches in the same line (so they could be coloured) to overrun the end of the current line. If another match was found, it was incorrectly shown (and then shown again when found in the next line). 7. If pcregrep was compiled under Windows, there was a reference to the function pcregrep_exit() before it was defined. I am assuming this was the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was reported by a user. I've moved the definition above the reference. Version 8.11 10-Dec-2010 ------------------------ 1. (*THEN) was not working properly if there were untried alternatives prior to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it backtracked to try for "b" instead of moving to the next alternative branch at the same level (in this case, to look for "c"). The Perl documentation is clear that when (*THEN) is backtracked onto, it goes to the "next alternative in the innermost enclosing group". 2. (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern such as (A(*COMMIT)B(*THEN)C|D) any failure after matching A should result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides (*THEN). 3. If \s appeared in a character class, it removed the VT character from the class, even if it had been included by some previous item, for example in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part of \s, but is part of the POSIX "space" class.) 4. A partial match never returns an empty string (because you can always match an empty string at the end of the subject); however the checking for an empty string was starting at the "start of match" point. This has been changed to the "earliest inspected character" point, because the returned data for a partial match starts at this character. This means that, for example, /(?<=abc)def/ gives a partial match for the subject "abc" (previously it gave "no match"). 5. Changes have been made to the way PCRE_PARTIAL_HARD affects the matching of $, \z, \Z, \b, and \B. If the match point is at the end of the string, previously a full match would be given. However, setting PCRE_PARTIAL_HARD has an implication that the given string is incomplete (because a partial match is preferred over a full match). For this reason, these items now give a partial match in this situation. [Aside: previously, the one case /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial match rather than a full match, which was wrong by the old rules, but is now correct.] 6. There was a bug in the handling of #-introduced comments, recognized when PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set. If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when scanning for the end of the comment. (*Character* 0x85 is an "any" newline, but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several places in pcre_compile(). 7. Related to (6) above, when pcre_compile() was skipping #-introduced comments when looking ahead for named forward references to subpatterns, the only newline sequence it recognized was NL. It now handles newlines according to the set newline convention. 8. SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the former, but used strtoul(), whereas pcretest avoided strtoul() but did not cater for a lack of strerror(). These oversights have been fixed. 9. Added --match-limit and --recursion-limit to pcregrep. 10. Added two casts needed to build with Visual Studio when NO_RECURSE is set. 11. When the -o option was used, pcregrep was setting a return code of 1, even when matches were found, and --line-buffered was not being honoured. 12. Added an optional parentheses number to the -o and --only-matching options of pcregrep. 13. Imitating Perl's /g action for multiple matches is tricky when the pattern can match an empty string. The code to do it in pcretest and pcredemo needed fixing: (a) When the newline convention was "crlf", pcretest got it wrong, skipping only one byte after an empty string match just before CRLF (this case just got forgotten; "any" and "anycrlf" were OK). (b) The pcretest code also had a bug, causing it to loop forever in UTF-8 mode when an empty string match preceded an ASCII character followed by a non-ASCII character. (The code for advancing by one character rather than one byte was nonsense.) (c) The pcredemo.c sample program did not have any code at all to handle the cases when CRLF is a valid newline sequence. 14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given as a starting offset was within the subject string. There is now a new error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is negative or greater than the length of the string. In order to test this, pcretest is extended to allow the setting of negative starting offsets. 15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the starting offset points to the beginning of a UTF-8 character was unnecessarily clumsy. I tidied it up. 16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD. 17. Nobody had reported that the --include_dir option, which was added in release 7.7 should have been called --include-dir (hyphen, not underscore) for compatibility with GNU grep. I have changed it to --include-dir, but left --include_dir as an undocumented synonym, and the same for --exclude-dir, though that is not available in GNU grep, at least as of release 2.5.4. 18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8 characters from a string of bytes) have been redefined so as not to use loops, in order to improve performance in some environments. At the same time, I abstracted some of the common code into auxiliary macros to save repetition (this should not affect the compiled code). 19. If \c was followed by a multibyte UTF-8 character, bad things happened. A compile-time error is now given if \c is not followed by an ASCII character, that is, a byte less than 128. (In EBCDIC mode, the code is different, and any byte value is allowed.) 20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_ START_OPTIMIZE option, which is now allowed at compile time - but just passed through to pcre_exec() or pcre_dfa_exec(). This makes it available to pcregrep and other applications that have no direct access to PCRE options. The new /Y option in pcretest sets this option when calling pcre_compile(). 21. Change 18 of release 8.01 broke the use of named subpatterns for recursive back references. Groups containing recursive back references were forced to be atomic by that change, but in the case of named groups, the amount of memory required was incorrectly computed, leading to "Failed: internal error: code overflow". This has been fixed. 22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and pcretest.c, to avoid build problems in some Borland environments. Version 8.10 25-Jun-2010 ------------------------ 1. Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and THEN. 2. (*ACCEPT) was not working when inside an atomic group. 3. Inside a character class, \B is treated as a literal by default, but faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option causes the error). The code is unchanged, but I tidied the documentation. 4. Inside a character class, PCRE always treated \R and \X as literals, whereas Perl faults them if its -w option is set. I have changed PCRE so that it faults them when PCRE_EXTRA is set. 5. Added support for \N, which always matches any character other than newline. (It is the same as "." when PCRE_DOTALL is not set.) 6. When compiling pcregrep with newer versions of gcc which may have FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite', declared with attribute warn_unused_result" were given. Just casting the result to (void) does not stop the warnings; a more elaborate fudge is needed. I've used a macro to implement this. 7. Minor change to pcretest.c to avoid a compiler warning. 8. Added four artifical Unicode properties to help with an option to make \s etc use properties (see next item). The new properties are: Xan (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word). 9. Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes use Unicode properties. (*UCP) at the start of a pattern can be used to set this option. Modified pcretest to add /W to test this facility. Added REG_UCP to make it available via the POSIX interface. 10. Added --line-buffered to pcregrep. 11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was studied, and the match started with a letter with a code point greater than 127 whose first byte was different to the first byte of the other case of the letter, the other case of this starting letter was not recognized (#976). 12. If a pattern that was studied started with a repeated Unicode property test, for example, \p{Nd}+, there was the theoretical possibility of setting up an incorrect bitmap of starting bytes, but fortunately it could not have actually happened in practice until change 8 above was made (it added property types that matched character-matching opcodes). 13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of possible starting bytes for non-anchored patterns. 14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes \R, and also a number of cases that involve Unicode properties, both explicit and implicit when PCRE_UCP is set. 15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8 input, it could crash or give wrong results if characters with values greater than 0xc0 were present in the subject string. (Detail: it assumed UTF-8 input when processing these items.) 16. Added a lot of (int) casts to avoid compiler warnings in systems where size_t is 64-bit (#991). 17. Added a check for running out of memory when PCRE is compiled with --disable-stack-for-recursion (#990). 18. If the last data line in a file for pcretest does not have a newline on the end, a newline was missing in the output. 19. The default pcre_chartables.c file recognizes only ASCII characters (values less than 128) in its various bitmaps. However, there is a facility for generating tables according to the current locale when PCRE is compiled. It turns out that in some environments, 0x85 and 0xa0, which are Unicode space characters, are recognized by isspace() and therefore were getting set in these tables, and indeed these tables seem to approximate to ISO 8859. This caused a problem in UTF-8 mode when pcre_study() was used to create a list of bytes that can start a match. For \s, it was including 0x85 and 0xa0, which of course cannot start UTF-8 characters. I have changed the code so that only real ASCII characters (less than 128) and the correct starting bytes for UTF-8 encodings are set for characters greater than 127 when in UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different altogether.) 20. Added the /T option to pcretest so as to be able to run tests with non- standard character tables, thus making it possible to include the tests used for 19 above in the standard set of tests. 21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward reference to a subpattern the other side of a comment that contains an opening parenthesis caused either an internal compiling error, or a reference to the wrong subpattern. Version 8.02 19-Mar-2010 ------------------------ 1. The Unicode data tables have been updated to Unicode 5.2.0. 2. Added the option --libs-cpp to pcre-config, but only when C++ support is configured. 3. Updated the licensing terms in the pcregexp.pas file, as agreed with the original author of that file, following a query about its status. 4. On systems that do not have stdint.h (e.g. Solaris), check for and include inttypes.h instead. This fixes a bug that was introduced by change 8.01/8. 5. A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive quantifier applied to a forward-referencing subroutine call, could compile incorrect code or give the error "internal error: previously-checked referenced subpattern not found". 6. Both MS Visual Studio and Symbian OS have problems with initializing variables to point to external functions. For these systems, therefore, pcre_malloc etc. are now initialized to local functions that call the relevant global functions. 7. There were two entries missing in the vectors called coptable and poptable in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors. I've fixed the data, and added a kludgy way of testing at compile time that the lengths are correct (equal to the number of opcodes). 8. Following on from 7, I added a similar kludge to check the length of the eint vector in pcreposix.c. 9. Error texts for pcre_compile() are held as one long string to avoid too much relocation at load time. To find a text, the string is searched, counting zeros. There was no check for running off the end of the string, which could happen if a new error number was added without updating the string. 10. \K gave a compile-time error if it appeared in a lookbehind assersion. 11. \K was not working if it appeared in an atomic group or in a group that was called as a "subroutine", or in an assertion. Perl 5.11 documents that \K is "not well defined" if used in an assertion. PCRE now accepts it if the assertion is positive, but not if it is negative. 12. Change 11 fortuitously reduced the size of the stack frame used in the "match()" function of pcre_exec.c by one pointer. Forthcoming implementation of support for (*MARK) will need an extra pointer on the stack; I have reserved it now, so that the stack frame size does not decrease. 13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other item in branch that calls a recursion is a subroutine call - as in the second branch in the above example - was incorrectly given the compile- time error "recursive call could loop indefinitely" because pcre_compile() was not correctly checking the subroutine for matching a non-empty string. 14. The checks for overrunning compiling workspace could trigger after an overrun had occurred. This is a "should never occur" error, but it can be triggered by pathological patterns such as hundreds of nested parentheses. The checks now trigger 100 bytes before the end of the workspace. 15. Fix typo in configure.ac: "srtoq" should be "strtoq". Version 8.01 19-Jan-2010 ------------------------ 1. If a pattern contained a conditional subpattern with only one branch (in particular, this includes all (*DEFINE) patterns), a call to pcre_study() computed the wrong minimum data length (which is of course zero for such subpatterns). This could cause incorrect "no match" results. 2. For patterns such as (?i)a(?-i)b|c where an option setting at the start of the pattern is reset in the first branch, pcre_compile() failed with "internal error: code overflow at offset...". This happened only when the reset was to the original external option setting. (An optimization abstracts leading options settings into an external setting, which was the cause of this.) 3. A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the assertion pattern did not match (meaning that the assertion was true), it was incorrectly treated as false if the SKIP had been reached during the matching. This also applied to assertions used as conditions. 4. If an item that is not supported by pcre_dfa_exec() was encountered in an assertion subpattern, including such a pattern used as a condition, unpredictable results occurred, instead of the error return PCRE_ERROR_DFA_UITEM. 5. The C++ GlobalReplace function was not working like Perl for the special situation when an empty string is matched. It now does the fancy magic stuff that is necessary. 6. In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been removed. (These were left over from very, very early versions of PCRE.) 7. Some cosmetic changes to the code to make life easier when compiling it as part of something else: (a) Change DEBUG to PCRE_DEBUG. (b) In pcre_compile(), rename the member of the "branch_chain" structure called "current" as "current_branch", to prevent a collision with the Linux macro when compiled as a kernel module. (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to prevent a collision with the Linux macro when compiled as a kernel module. 8. In pcre_compile() there are some checks for integer overflows that used to cast potentially large values to (double). This has been changed to that when building, a check for int64_t is made, and if it is found, it is used instead, thus avoiding the use of floating point arithmetic. (There is no other use of FP in PCRE.) If int64_t is not found, the fallback is to double. 9. Added two casts to avoid signed/unsigned warnings from VS Studio Express 2005 (difference between two addresses compared to an unsigned value). 10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a custom one, because of the following reported problem in Windows: - libbz2 uses the Pascal calling convention (WINAPI) for the functions under Win32. - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h", therefore missing the function definition. - The compiler thus generates a "C" signature for the test function. - The linker fails to find the "C" function. - PCRE fails to configure if asked to do so against libbz2. 11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these messages were output: Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and rerunning libtoolize, to keep the correct libtool macros in-tree. Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am. I have done both of these things. 12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec() most of the time, it *can* run out if it is given a pattern that contains a runaway infinite recursion. I updated the discussion in the pcrestack man page. 13. Now that we have gone to the x.xx style of version numbers, the minor version may start with zero. Using 08 or 09 is a bad idea because users might check the value of PCRE_MINOR in their code, and 08 or 09 may be interpreted as invalid octal numbers. I've updated the previous comment in configure.ac, and also added a check that gives an error if 08 or 09 are used. 14. Change 8.00/11 was not quite complete: code had been accidentally omitted, causing partial matching to fail when the end of the subject matched \W in a UTF-8 pattern where \W was quantified with a minimum of 3. 15. There were some discrepancies between the declarations in pcre_internal.h of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and their definitions. The declarations used "const uschar *" and the definitions used USPTR. Even though USPTR is normally defined as "const unsigned char *" (and uschar is typedeffed as "unsigned char"), it was reported that: "This difference in casting confuses some C++ compilers, for example, SunCC recognizes above declarations as different functions and generates broken code for hbpcre." I have changed the declarations to use USPTR. 16. GNU libtool is named differently on some systems. The autogen.sh script now tries several variants such as glibtoolize (MacOSX) and libtoolize1x (FreeBSD). 17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00 (strtoXX undefined when compiling pcrecpp.cc). The patch contains this comment: "Figure out how to create a longlong from a string: strtoll and equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for instance, but it only takes 2 args instead of 3!" 18. A subtle bug concerned with back references has been fixed by a change of specification, with a corresponding code fix. A pattern such as ^(xa|=?\1a)+$ which contains a back reference inside the group to which it refers, was giving matches when it shouldn't. For example, xa=xaaa would match that pattern. Interestingly, Perl (at least up to 5.11.3) has the same bug. Such groups have to be quantified to be useful, or contained inside another quantified group. (If there's no repetition, the reference can never match.) The problem arises because, having left the group and moved on to the rest of the pattern, a later failure that backtracks into the group uses the captured value from the final iteration of the group rather than the correct earlier one. I have fixed this in PCRE by forcing any group that contains a reference to itself to be an atomic group; that is, there cannot be any backtracking into it once it has completed. This is similar to recursive and subroutine calls. Version 8.00 19-Oct-09 ---------------------- 1. The table for translating pcre_compile() error codes into POSIX error codes was out-of-date, and there was no check on the pcre_compile() error code being within the table. This could lead to an OK return being given in error. 2. Changed the call to open a subject file in pcregrep from fopen(pathname, "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests in a Windows environment. 3. The pcregrep --count option prints the count for each file even when it is zero, as does GNU grep. However, pcregrep was also printing all files when --files-with-matches was added. Now, when both options are given, it prints counts only for those files that have at least one match. (GNU grep just prints the file name in this circumstance, but including the count seems more useful - otherwise, why use --count?) Also ensured that the combination -clh just lists non-zero counts, with no names. 4. The long form of the pcregrep -F option was incorrectly implemented as --fixed_strings instead of --fixed-strings. This is an incompatible change, but it seems right to fix it, and I didn't think it was worth preserving the old behaviour. 5. The command line items --regex=pattern and --regexp=pattern were not recognized by pcregrep, which required --regex pattern or --regexp pattern (with a space rather than an '='). The man page documented the '=' forms, which are compatible with GNU grep; these now work. 6. No libpcreposix.pc file was created for pkg-config; there was just libpcre.pc and libpcrecpp.pc. The omission has been rectified. 7. Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size when UCP support is not needed, by modifying the Python script that generates it from Unicode data files. This should not matter if the module is correctly used as a library, but I received one complaint about 50K of unwanted data. My guess is that the person linked everything into his program rather than using a library. Anyway, it does no harm. 8. A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger was a minimum greater than 1 for a wide character in a possessive repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8 which had an unlimited repeat of a nested, fixed maximum repeat of a wide character. Chaos in the form of incorrect output or a compiling loop could result. 9. The restrictions on what a pattern can contain when partial matching is requested for pcre_exec() have been removed. All patterns can now be partially matched by this function. In addition, if there are at least two slots in the offset vector, the offset of the earliest inspected character for the match and the offset of the end of the subject are set in them when PCRE_ERROR_PARTIAL is returned. 10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is synonymous with PCRE_PARTIAL, for backwards compatibility, and PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match, and may be more useful for multi-segment matching. 11. Partial matching with pcre_exec() is now more intuitive. A partial match used to be given if ever the end of the subject was reached; now it is given only if matching could not proceed because another character was needed. This makes a difference in some odd cases such as Z(*FAIL) with the string "Z", which now yields "no match" instead of "partial match". In the case of pcre_dfa_exec(), "no match" is given if every matching path for the final character ended with (*FAIL). 12. Restarting a match using pcre_dfa_exec() after a partial match did not work if the pattern had a "must contain" character that was already found in the earlier partial match, unless partial matching was again requested. For example, with the pattern /dog.(body)?/, the "must contain" character is "g". If the first part-match was for the string "dog", restarting with "sbody" failed. This bug has been fixed. 13. The string returned by pcre_dfa_exec() after a partial match has been changed so that it starts at the first inspected character rather than the first character of the match. This makes a difference only if the pattern starts with a lookbehind assertion or \b or \B (\K is not supported by pcre_dfa_exec()). It's an incompatible change, but it makes the two matching functions compatible, and I think it's the right thing to do. 14. Added a pcredemo man page, created automatically from the pcredemo.c file, so that the demonstration program is easily available in environments where PCRE has not been installed from source. 15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp, libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared library. 16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user. It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it is not the first non-POSIX option to be added. Clearly some people find these options useful. 17. If a caller to the POSIX matching function regexec() passes a non-zero value for nmatch with a NULL value for pmatch, the value of nmatch is forced to zero. 18. RunGrepTest did not have a test for the availability of the -u option of the diff command, as RunTest does. It now checks in the same way as RunTest, and also checks for the -b option. 19. If an odd number of negated classes containing just a single character interposed, within parentheses, between a forward reference to a named subpattern and the definition of the subpattern, compilation crashed with an internal error, complaining that it could not find the referenced subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/. [The bug was that it was starting one character too far in when skipping over the character class, thus treating the ] as data rather than terminating the class. This meant it could skip too much.] 20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the /g option in pcretest when the pattern contains \K, which makes it possible to have an empty string match not at the start, even when the pattern is anchored. Updated pcretest and pcredemo to use this option. 21. If the maximum number of capturing subpatterns in a recursion was greater than the maximum at the outer level, the higher number was returned, but with unset values at the outer level. The correct (outer level) value is now given. 22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of PCRE did not set those parentheses (unlike Perl). I have now found a way to make it do so. The string so far is captured, making this feature compatible with Perl. 23. The tests have been re-organized, adding tests 11 and 12, to make it possible to check the Perl 5.10 features against Perl 5.10. 24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine pattern matches a fixed length string. PCRE did not allow this; now it does. Neither allows recursion. 25. I finally figured out how to implement a request to provide the minimum length of subject string that was needed in order to match a given pattern. (It was back references and recursion that I had previously got hung up on.) This code has now been added to pcre_study(); it finds a lower bound to the length of subject needed. It is not necessarily the greatest lower bound, but using it to avoid searching strings that are too short does give some useful speed-ups. The value is available to calling programs via pcre_fullinfo(). 26. While implementing 25, I discovered to my embarrassment that pcretest had not been passing the result of pcre_study() to pcre_dfa_exec(), so the study optimizations had never been tested with that matching function. Oops. What is worse, even when it was passed study data, there was a bug in pcre_dfa_exec() that meant it never actually used it. Double oops. There were also very few tests of studied patterns with pcre_dfa_exec(). 27. If (?| is used to create subpatterns with duplicate numbers, they are now allowed to have the same name, even if PCRE_DUPNAMES is not set. However, on the other side of the coin, they are no longer allowed to have different names, because these cannot be distinguished in PCRE, and this has caused confusion. (This is a difference from Perl.) 28. When duplicate subpattern names are present (necessarily with different numbers, as required by 27 above), and a test is made by name in a conditional pattern, either for a subpattern having been matched, or for recursion in such a pattern, all the associated numbered subpatterns are tested, and the overall condition is true if the condition is true for any one of them. This is the way Perl works, and is also more like the way testing by number works. Version 7.9 11-Apr-09 --------------------- 1. When building with support for bzlib/zlib (pcregrep) and/or readline (pcretest), all targets were linked against these libraries. This included libpcre, libpcreposix, and libpcrecpp, even though they do not use these libraries. This caused unwanted dependencies to be created. This problem has been fixed, and now only pcregrep is linked with bzlib/zlib and only pcretest is linked with readline. 2. The "typedef int BOOL" in pcre_internal.h that was included inside the "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been moved outside it again, because FALSE and TRUE are already defined in AIX, but BOOL is not. 3. The pcre_config() function was treating the PCRE_MATCH_LIMIT and PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints. 4. The pcregrep documentation said spaces were inserted as well as colons (or hyphens) following file names and line numbers when outputting matching lines. This is not true; no spaces are inserted. I have also clarified the wording for the --colour (or --color) option. 5. In pcregrep, when --colour was used with -o, the list of matching strings was not coloured; this is different to GNU grep, so I have changed it to be the same. 6. When --colo(u)r was used in pcregrep, only the first matching substring in each matching line was coloured. Now it goes on to look for further matches of any of the test patterns, which is the same behaviour as GNU grep. 7. A pattern that could match an empty string could cause pcregrep to loop; it doesn't make sense to accept an empty string match in pcregrep, so I have locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this seems to be how GNU grep behaves. [But see later change 40 for release 8.33.] 8. The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at start or after a newline", because the conditional assertion was not being correctly handled. The rule now is that both the assertion and what follows in the first alternative must satisfy the test. 9. If auto-callout was enabled in a pattern with a conditional group whose condition was an assertion, PCRE could crash during matching, both with pcre_exec() and pcre_dfa_exec(). 10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was used for matching. 11. Unicode property support in character classes was not working for characters (bytes) greater than 127 when not in UTF-8 mode. 12. Added the -M command line option to pcretest. 14. Added the non-standard REG_NOTEMPTY option to the POSIX interface. 15. Added the PCRE_NO_START_OPTIMIZE match-time option. 16. Added comments and documentation about mis-use of no_arg in the C++ wrapper. 17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch from Martin Jerabek that uses macro names for all relevant character and string constants. 18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of these, but not everybody uses configure. 19. A conditional group that had only one branch was not being correctly recognized as an item that could match an empty string. This meant that an enclosing group might also not be so recognized, causing infinite looping (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$ with the subject "ab", where knowledge that the repeated group can match nothing is needed in order to break the loop. 20. If a pattern that was compiled with callouts was matched using pcre_dfa_ exec(), but without supplying a callout function, matching went wrong. 21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory leak if the size of the offset vector was greater than 30. When the vector is smaller, the saved offsets during recursion go onto a local stack vector, but for larger vectors malloc() is used. It was failing to free when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal" error, in fact). 22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the heapframe that is used only when UTF-8 support is enabled. This caused no problem, but was untidy. 23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is included within another project. 24. Steven Van Ingelgem's patches to add more options to the CMake support, slightly modified by me: (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including not building pcregrep. (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep. 25. Forward references, both numeric and by name, in patterns that made use of duplicate group numbers, could behave incorrectly or give incorrect errors, because when scanning forward to find the reference group, PCRE was not taking into account the duplicate group numbers. A pattern such as ^X(?3)(a)(?|(b)|(q))(Y) is an example. 26. Changed a few more instances of "const unsigned char *" to USPTR, making the feature of a custom pointer more persuasive (as requested by a user). 27. Wrapped the definitions of fileno and isatty for Windows, which appear in pcretest.c, inside #ifndefs, because it seems they are sometimes already pre-defined. 28. Added support for (*UTF8) at the start of a pattern. 29. Arrange for flags added by the "release type" setting in CMake to be shown in the configuration summary. Version 7.8 05-Sep-08 --------------------- 1. Replaced UCP searching code with optimized version as implemented for Ad Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two- stage table and inline lookup instead of a function, giving speed ups of 2 to 5 times on some simple patterns that I tested. Permission was given to distribute the MultiStage2.py script that generates the tables (it's not in the tarball, but is in the Subversion repository). 2. Updated the Unicode datatables to Unicode 5.1.0. This adds yet more scripts. 3. Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained a group with a zero qualifier. The result of the study could be incorrect, or the function might crash, depending on the pattern. 4. Caseless matching was not working for non-ASCII characters in back references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}. It now works when Unicode Property Support is available. 5. In pcretest, an escape such as \x{de} in the data was always generating a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in non-UTF-8 mode. If the value is greater than 255, it gives a warning about truncation. 6. Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...). 7. Added two (int) casts to pcregrep when printing the difference of two pointers, in case they are 64-bit values. 8. Added comments about Mac OS X stack usage to the pcrestack man page and to test 2 if it fails. 9. Added PCRE_CALL_CONVENTION just before the names of all exported functions, and a #define of that name to empty if it is not externally set. This is to allow users of MSVC to set it if necessary. 10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from the convenience functions in the pcre_get.c source file. 11. An option change at the start of a pattern that had top-level alternatives could cause overwriting and/or a crash. This command provoked a crash in some environments: printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest This potential security problem was recorded as CVE-2008-2371. 12. For a pattern where the match had to start at the beginning or immediately after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and pcre_dfa_exec() could read past the end of the passed subject if there was no match. To help with detecting such bugs (e.g. with valgrind), I modified pcretest so that it places the subject at the end of its malloc-ed buffer. 13. The change to pcretest in 12 above threw up a couple more cases when pcre_ exec() might read past the end of the data buffer in UTF-8 mode. 14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and the data contained the byte 0x85 as part of a UTF-8 character within its first line. This applied both to normal and DFA matching. 15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example, /^[^d]*?$/8 failed to match "abc". 16. Added a missing copyright notice to pcrecpp_internal.h. 17. Make it more clear in the documentation that values returned from pcre_exec() in ovector are byte offsets, not character counts. 18. Tidied a few places to stop certain compilers from issuing warnings. 19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as supplied by Stefan Weber. I made a further small update for 7.8 because there is a change of source arrangements: the pcre_searchfuncs.c module is replaced by pcre_ucd.c. Version 7.7 07-May-08 --------------------- 1. Applied Craig's patch to sort out a long long problem: "If we can't convert a string to a long long, pretend we don't even have a long long." This is done by checking for the strtoq, strtoll, and _strtoi64 functions. 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with pre-7.6 versions, which defined a global no_arg variable instead of putting it in the RE class. (See also #8 below.) 3. Remove a line of dead code, identified by coverity and reported by Nuno Lopes. 4. Fixed two related pcregrep bugs involving -r with --include or --exclude: (1) The include/exclude patterns were being applied to the whole pathnames of files, instead of just to the final components. (2) If there was more than one level of directory, the subdirectories were skipped unless they satisfied the include/exclude conditions. This is inconsistent with GNU grep (and could even be seen as contrary to the pcregrep specification - which I improved to make it absolutely clear). The action now is always to scan all levels of directory, and just apply the include/exclude patterns to regular files. 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used --exclude_dir in the tests to avoid scanning .svn directories. 6. Applied Craig's patch to the QuoteMeta function so that it escapes the NUL character as backslash + 0 rather than backslash + NUL, because PCRE doesn't support NULs in patterns. 7. Added some missing "const"s to declarations of static tables in pcre_compile.c and pcre_dfa_exec.c. 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was caused by fix #2 above. (Subsequently also a second patch to fix the first patch. And a third patch - this was a messy problem.) 9. Applied Craig's patch to remove the use of push_back(). 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX matching function regexec(). 11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n', which, however, unlike Perl's \g{...}, are subroutine calls, not back references. PCRE supports relative numbers with this syntax (I don't think Oniguruma does). 12. Previously, a group with a zero repeat such as (...){0} was completely omitted from the compiled regex. However, this means that if the group was called as a subroutine from elsewhere in the pattern, things went wrong (an internal error was given). Such groups are now left in the compiled pattern, with a new opcode that causes them to be skipped at execution time. 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes to the way PCRE behaves: (a) A lone ] character is dis-allowed (Perl treats it as data). (b) A back reference to an unmatched subpattern matches an empty string (Perl fails the current match path). (c) A data ] in a character class must be notated as \] because if the first data character in a class is ], it defines an empty class. (In Perl it is not possible to have an empty class.) The empty class [] never matches; it forces failure and is equivalent to (*FAIL) or (?!). The negative empty class [^] matches any one character, independently of the DOTALL setting. 14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a non-existent subpattern following a character class starting with ']' and containing () gave an internal compiling error instead of "reference to non-existent subpattern". Fortunately, when the pattern did exist, the compiled code was correct. (When scanning forwards to check for the existence of the subpattern, it was treating the data ']' as terminating the class, so got the count wrong. When actually compiling, the reference was subsequently set up correctly.) 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile; it was being rejected as not supported by pcre_dfa_exec(), even though other assertions are supported. I have made pcre_dfa_exec() support (*FAIL). 16. The implementation of 13c above involved the invention of a new opcode, OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s cannot be changed at match time, I realized I could make a small improvement to matching performance by compiling OP_ALLANY instead of OP_ANY for "." when DOTALL was set, and then removing the runtime tests on the OP_ANY path. 17. Compiling pcretest on Windows with readline support failed without the following two fixes: (1) Make the unistd.h include conditional on HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno. 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the ncurses library to be included for pcretest when ReadLine support is requested, but also to allow for it to be overridden. This patch came from Daniel Bergström. 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused any errors with the current Unicode tables. Thanks to Peter Kankowski for spotting this. Version 7.6 28-Jan-08 --------------------- 1. A character class containing a very large number of characters with codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer overflow. 2. Patch to cut out the "long long" test in pcrecpp_unittest when HAVE_LONG_LONG is not defined. 3. Applied Christian Ehrlicher's patch to update the CMake build files to bring them up to date and include new features. This patch includes: - Fixed PH's badly added libz and libbz2 support. - Fixed a problem with static linking. - Added pcredemo. [But later removed - see 7 below.] - Fixed dftables problem and added an option. - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and HAVE_LONG_LONG. - Added readline support for pcretest. - Added an listing of the option settings after cmake has run. 4. A user submitted a patch to Makefile that makes it easy to create "pcre.dll" under mingw when using Configure/Make. I added stuff to Makefile.am that cause it to include this special target, without affecting anything else. Note that the same mingw target plus all the other distribution libraries and programs are now supported when configuring with CMake (see 6 below) instead of with Configure/Make. 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code. This is an attempt to solve the reported problem "pcrecpp::no_arg is not exported in the Windows port". It has not yet been confirmed that the patch solves the problem, but it does no harm. 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured with CMake, and also correct the comment about stack recursion. 7. Remove the automatic building of pcredemo from the ./configure system and from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example of a program that users should build themselves after PCRE is installed, so building it automatically is not really right. What is more, it gave trouble in some build environments. 8. Further tidies to CMakeLists.txt from Sheri and Christian. Version 7.5 10-Jan-08 --------------------- 1. Applied a patch from Craig: "This patch makes it possible to 'ignore' values in parens when parsing an RE using the C++ wrapper." 2. Negative specials like \S did not work in character classes in UTF-8 mode. Characters greater than 255 were excluded from the class instead of being included. 3. The same bug as (2) above applied to negated POSIX classes such as [:^space:]. 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it defined or documented. It seems to have been a typo for PCRE_STATIC, so I have changed it. 5. The construct (?&) was not diagnosed as a syntax error (it referenced the first named subpattern) and a construct such as (?&a) would reference the first named subpattern whose name started with "a" (in other words, the length check was missing). Both these problems are fixed. "Subpattern name expected" is now given for (?&) (a zero-length name), and this patch also makes it give the same error for \k'' (previously it complained that that was a reference to a non-existent subpattern). 6. The erroneous patterns (?+-a) and (?-+a) give different error messages; this is right because (?- can be followed by option settings as well as by digits. I have, however, made the messages clearer. 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns than the number used in the conditional) now cause a compile-time error. This is actually not compatible with Perl, which accepts such patterns, but treats the conditional as always being FALSE (as PCRE used to), but it seems to me that giving a diagnostic is better. 8. Change "alphameric" to the more common word "alphanumeric" in comments and messages. 9. Fix two occurrences of "backslash" in comments that should have been "backspace". 10. Remove two redundant lines of code that can never be obeyed (their function was moved elsewhere). 11. The program that makes PCRE's Unicode character property table had a bug which caused it to generate incorrect table entries for sequences of characters that have the same character type, but are in different scripts. It amalgamated them into a single range, with the script of the first of them. In other words, some characters were in the wrong script. There were thirteen such cases, affecting characters in the following ranges: U+002b0 - U+002c1 U+0060c - U+0060d U+0061e - U+00612 U+0064b - U+0065e U+0074d - U+0076d U+01800 - U+01805 U+01d00 - U+01d77 U+01d9b - U+01dbf U+0200b - U+0200f U+030fc - U+030fe U+03260 - U+0327f U+0fb46 - U+0fbb1 U+10450 - U+1049d 12. The -o option (show only the matching part of a line) for pcregrep was not compatible with GNU grep in that, if there was more than one match in a line, it showed only the first of them. It now behaves in the same way as GNU grep. 13. If the -o and -v options were combined for pcregrep, it printed a blank line for every non-matching line. GNU grep prints nothing, and pcregrep now does the same. The return code can be used to tell if there were any non-matching lines. 14. Added --file-offsets and --line-offsets to pcregrep. 15. The pattern (?=something)(?R) was not being diagnosed as a potentially infinitely looping recursion. The bug was that positive lookaheads were not being skipped when checking for a possible empty match (negative lookaheads and both kinds of lookbehind were skipped). 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the inclusion of <windows.h> to before rather than after the definition of INVALID_FILE_ATTRIBUTES (patch from David Byron). 17. Specifying a possessive quantifier with a specific limit for a Unicode character property caused pcre_compile() to compile bad code, which led at runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that caused the error; without that there was no problem. 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2. 19. Added --enable-pcretest-libreadline. 20. In pcrecpp.cc, the variable 'count' was incremented twice in RE::GlobalReplace(). As a result, the number of replacements returned was double what it should be. I removed one of the increments, but Craig sent a later patch that removed the other one (the right fix) and added unit tests that check the return values (which was not done before). 21. Several CMake things: (1) Arranged that, when cmake is used on Unix, the libraries end up with the names libpcre and libpcreposix, not just pcre and pcreposix. (2) The above change means that pcretest and pcregrep are now correctly linked with the newly-built libraries, not previously installed ones. (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2. 22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.* crashed when matching a string such as a\x{2029}b (note that \x{2029} is a UTF-8 newline character). The key issue is that the pattern starts .*; this means that the match must be either at the beginning, or after a newline. The bug was in the code for advancing after a failed match and checking that the new position followed a newline. It was not taking account of UTF-8 characters correctly. 23. PCRE was behaving differently from Perl in the way it recognized POSIX character classes. PCRE was not treating the sequence [:...:] as a character class unless the ... were all letters. Perl, however, seems to allow any characters between [: and :], though of course it rejects as unknown any "names" that contain non-letters, because all the known class names consist only of letters. Thus, Perl gives an error for [[:1234:]], for example, whereas PCRE did not - it did not recognize a POSIX character class. This seemed a bit dangerous, so the code has been changed to be closer to Perl. The behaviour is not identical to Perl, because PCRE will diagnose an unknown class for, for example, [[:l\ower:]] where Perl will treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where Perl does, and where it didn't before. 24. Rewrite so as to remove the single use of %n from pcregrep because in some Windows environments %n is disabled by default. Version 7.4 21-Sep-07 --------------------- 1. Change 7.3/28 was implemented for classes by looking at the bitmap. This means that a class such as [\s] counted as "explicit reference to CR or LF". That isn't really right - the whole point of the change was to try to help when there was an actual mention of one of the two characters. So now the change happens only if \r or \n (or a literal CR or LF) character is encountered. 2. The 32-bit options word was also used for 6 internal flags, but the numbers of both had grown to the point where there were only 3 bits left. Fortunately, there was spare space in the data structure, and so I have moved the internal flags into a new 16-bit field to free up more option bits. 3. The appearance of (?J) at the start of a pattern set the DUPNAMES option, but did not set the internal JCHANGED flag - either of these is enough to control the way the "get" function works - but the PCRE_INFO_JCHANGED facility is supposed to tell if (?J) was ever used, so now (?J) at the start sets both bits. 4. Added options (at build time, compile time, exec time) to change \R from matching any Unicode line ending sequence to just matching CR, LF, or CRLF. 5. doc/pcresyntax.html was missing from the distribution. 6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward compatibility, even though it is no longer used. 7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and strtoull to pcrecpp.cc to select the available functions in WIN32 when the windows.h file is present (where different names are used). [This was reversed later after testing - see 16 below.] 8. Changed all #include <config.h> to #include "config.h". There were also some further <pcre.h> cases that I changed to "pcre.h". 9. When pcregrep was used with the --colour option, it missed the line ending sequence off the lines that it output. 10. It was pointed out to me that arrays of string pointers cause lots of relocations when a shared library is dynamically loaded. A technique of using a single long string with a table of offsets can drastically reduce these. I have refactored PCRE in four places to do this. The result is dramatic: Originally: 290 After changing UCP table: 187 After changing error message table: 43 After changing table of "verbs" 36 After changing table of Posix names 22 Thanks to the folks working on Gregex for glib for this insight. 11. --disable-stack-for-recursion caused compiling to fail unless -enable- unicode-properties was also set. 12. Updated the tests so that they work when \R is defaulted to ANYCRLF. 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously checked only for CRLF. 14. Added casts to pcretest.c to avoid compiler warnings. 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings. 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working, and instead check for _strtoi64 explicitly, and avoid the use of snprintf() entirely. This removes changes made in 7 above. 17. The CMake files have been updated, and there is now more information about building with CMake in the NON-UNIX-USE document. Version 7.3 28-Aug-07 --------------------- 1. In the rejigging of the build system that eventually resulted in 7.1, the line "#include <pcre.h>" was included in pcre_internal.h. The use of angle brackets there is not right, since it causes compilers to look for an installed pcre.h, not the version that is in the source that is being compiled (which of course may be different). I have changed it back to: #include "pcre.h" I have a vague recollection that the change was concerned with compiling in different directories, but in the new build system, that is taken care of by the VPATH setting the Makefile. 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed when the subject happened to end in the byte 0x85 (e.g. if the last character was \x{1ec5}). *Character* 0x85 is one of the "any" newline characters but of course it shouldn't be taken as a newline when it is part of another character. The bug was that, for an unlimited repeat of . in not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by characters when looking for a newline. 3. A small performance improvement in the DOTALL UTF-8 mode .* case. 4. Debugging: adjusted the names of opcodes for different kinds of parentheses in debug output. 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for long printing in the pcrecpp unittest when running under MinGW. 6. ESC_K was left out of the EBCDIC table. 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing parentheses; I made it 1000, which seemed large enough. Unfortunately, the limit also applies to "virtual nesting" when a pattern is recursive, and in this case 1000 isn't so big. I have been able to remove this limit at the expense of backing off one optimization in certain circumstances. Normally, when pcre_exec() would call its internal match() function recursively and immediately return the result unconditionally, it uses a "tail recursion" feature to save stack. However, when a subpattern that can match an empty string has an unlimited repetition quantifier, it no longer makes this optimization. That gives it a stack frame in which to save the data for checking that an empty string has been matched. Previously this was taken from the 1000-entry workspace that had been reserved. So now there is no explicit limit, but more stack is used. 8. Applied Daniel's patches to solve problems with the import/export magic syntax that is required for Windows, and which was going wrong for the pcreposix and pcrecpp parts of the library. These were overlooked when this problem was solved for the main library. 9. There were some crude static tests to avoid integer overflow when computing the size of patterns that contain repeated groups with explicit upper limits. As the maximum quantifier is 65535, the maximum group length was set at 30,000 so that the product of these two numbers did not overflow a 32-bit integer. However, it turns out that people want to use groups that are longer than 30,000 bytes (though not repeat them that many times). Change 7.0/17 (the refactoring of the way the pattern size is computed) has made it possible to implement the integer overflow checks in a much more dynamic way, which I have now done. The artificial limitation on group length has been removed - we now have only the limit on the total length of the compiled pattern, which depends on the LINK_SIZE setting. 10. Fixed a bug in the documentation for get/copy named substring when duplicate names are permitted. If none of the named substrings are set, the functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an empty string. 11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error, because the ] is interpreted as the first data character and the terminating ] is not found. PCRE has been made compatible with Perl in this regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could cause memory overwriting. 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty string has been matched (to stop an infinite loop). It was not recognizing a conditional subpattern that could match an empty string if that subpattern was within another subpattern. For example, it looped when trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the condition was not nested. This bug has been fixed. 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack past the start of the subject in the presence of bytes with the top bit set, for example "\x8aBCD". 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE), (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT). 14. Optimized (?!) to (*FAIL). 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629. This restricts code points to be within the range 0 to 0x10FFFF, excluding the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still does: it's just the validity check that is more restrictive. 16. Inserted checks for integer overflows during escape sequence (backslash) processing, and also fixed erroneous offset values for syntax errors during backslash processing. 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above) for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80". 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference" caused an overrun. 19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with something other than just ASCII characters) inside a group that had an unlimited repeat caused a loop at compile time (while checking to see whether the group could match an empty string). 20. Debugging a pattern containing \p or \P could cause a crash. For example, [\P{Any}] did so. (Error in the code for printing property names.) 21. An orphan \E inside a character class could cause a crash. 22. A repeated capturing bracket such as (A)? could cause a wild memory reference during compilation. 23. There are several functions in pcre_compile() that scan along a compiled expression for various reasons (e.g. to see if it's fixed length for look behind). There were bugs in these functions when a repeated \p or \P was present in the pattern. These operators have additional parameters compared with \d, etc, and these were not being taken into account when moving along the compiled data. Specifically: (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed length. (b) An item such as \pL+ within a repeated group could cause crashes or loops. (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect "reference to non-existent subpattern" error. (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time. 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte characters were involved (for example /\S{2}/8g with "A\x{a3}BC"). 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop. 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other character were causing crashes (broken optimization). 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing \p or \P) caused a compile-time loop. 28. More problems have arisen in unanchored patterns when CRLF is a valid line break. For example, the unstudied pattern [\r\n]A does not match the string "\r\nA" because change 7.0/46 below moves the current point on by two characters after failing to match at the start. However, the pattern \nA *does* match, because it doesn't start till \n, and if [\r\n]A is studied, the same is true. There doesn't seem any very clean way out of this, but what I have chosen to do makes the common cases work: PCRE now takes note of whether there can be an explicit match for \r or \n anywhere in the pattern, and if so, 7.0/46 no longer applies. As part of this change, there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled pattern has explicit CR or LF references. 29. Added (*CR) etc for changing newline setting at start of pattern. Version 7.2 19-Jun-07 --------------------- 1. If the fr_FR locale cannot be found for test 3, try the "french" locale, which is apparently normally available under Windows. 2. Re-jig the pcregrep tests with different newline settings in an attempt to make them independent of the local environment's newline setting. 3. Add code to configure.ac to remove -g from the CFLAGS default settings. 4. Some of the "internals" tests were previously cut out when the link size was not 2, because the output contained actual offsets. The recent new "Z" feature of pcretest means that these can be cut out, making the tests usable with all link sizes. 5. Implemented Stan Switzer's goto replacement for longjmp() when not using stack recursion. This gives a massive performance boost under BSD, but just a small improvement under Linux. However, it saves one field in the frame in all cases. 6. Added more features from the forthcoming Perl 5.10: (a) (?-n) (where n is a string of digits) is a relative subroutine or recursion call. It refers to the nth most recently opened parentheses. (b) (?+n) is also a relative subroutine call; it refers to the nth next to be opened parentheses. (c) Conditions that refer to capturing parentheses can be specified relatively, for example, (?(-2)... or (?(+3)... (d) \K resets the start of the current match so that everything before is not part of it. (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible). (f) \g{name} is another synonym - part of Perl 5.10's unification of reference syntax. (g) (?| introduces a group in which the numbering of parentheses in each alternative starts with the same number. (h) \h, \H, \v, and \V match horizontal and vertical whitespace. 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and PCRE_INFO_JCHANGED. 8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not terminating or by crashing. Diagnosed by Viktor Griph; it was in the code for detecting groups that can match an empty string. 9. A pattern with a very large number of alternatives (more than several hundred) was running out of internal workspace during the pre-compile phase, where pcre_compile() figures out how much memory will be needed. A bit of new cunning has reduced the workspace needed for groups with alternatives. The 1000-alternative test pattern now uses 12 bytes of workspace instead of running out of the 4096 that are available. 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings. 11. Applied patch from Google to remove an optimization that didn't quite work. The report of the bug said: pcrecpp::RE("a*").FullMatch("aaa") matches, while pcrecpp::RE("a*?").FullMatch("aaa") does not, and pcrecpp::RE("a*?\\z").FullMatch("aaa") does again. 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127 it matched the wrong number of bytes. Version 7.1 24-Apr-07 --------------------- 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one that is more "standard", making use of automake and other Autotools. There is some re-arrangement of the files and adjustment of comments consequent on this. 2. Part of the patch fixed a problem with the pcregrep tests. The test of -r for recursive directory scanning broke on some systems because the files are not scanned in any specific order and on different systems the order was different. A call to "sort" has been inserted into RunGrepTest for the approprate test as a short-term fix. In the longer term there may be an alternative. 3. I had an email from Eric Raymond about problems translating some of PCRE's man pages to HTML (despite the fact that I distribute HTML pages, some people do their own conversions for various reasons). The problems concerned the use of low-level troff macros .br and .in. I have therefore removed all such uses from the man pages (some were redundant, some could be replaced by .nf/.fi pairs). The 132html script that I use to generate HTML has been updated to handle .nf/.fi and to complain if it encounters .br or .in. 4. Updated comments in configure.ac that get placed in config.h.in and also arranged for config.h to be included in the distribution, with the name config.h.generic, for the benefit of those who have to compile without Autotools (compare pcre.h, which is now distributed as pcre.h.generic). 5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan Weber: (1) pcre_internal.h was missing some function renames; (2) updated makevp.bat for the current PCRE, using the additional files makevp_c.txt, makevp_l.txt, and pcregexp.pas. 6. A Windows user reported a minor discrepancy with test 2, which turned out to be caused by a trailing space on an input line that had got lost in his copy. The trailing space was an accident, so I've just removed it. 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told that is needed. 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c) as "const" (a) because they are and (b) because it helps the PHP maintainers who have recently made a script to detect big data structures in the php code that should be moved to the .rodata section. I remembered to update Builducptable as well, so it won't revert if ucptable.h is ever re-created. 9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c, pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in order to be able to cut out the UTF-8 tables in the latter when UTF-8 support is not required. This saves 1.5-2K of code, which is important in some applications. Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c so as not to refer to the tables, even though these functions will never be called when UTF-8 support is disabled. Otherwise there are problems with a shared library. 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h: (a) It was defining its arguments as char * instead of void *. (b) It was assuming that all moves were upwards in memory; this was true a long time ago when I wrote it, but is no longer the case. The emulated memove() is provided for those environments that have neither memmove() nor bcopy(). I didn't think anyone used it these days, but that is clearly not the case, as these two bugs were recently reported. 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt, and Detrail to create the HTML documentation, the .txt form of the man pages, and it removes trailing spaces from listed files. It also creates pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter case, it wraps all the #defines with #ifndefs. This script should be run before "make dist". 12. Fixed two fairly obscure bugs concerned with quantified caseless matching with Unicode property support. (a) For a maximizing quantifier, if the two different cases of the character were of different lengths in their UTF-8 codings (there are some cases like this - I found 11), and the matching function had to back up over a mixture of the two cases, it incorrectly assumed they were both the same length. (b) When PCRE was configured to use the heap rather than the stack for recursion during matching, it was not correctly preserving the data for the other case of a UTF-8 character when checking ahead for a match while processing a minimizing repeat. If the check also involved matching a wide character, but failed, corruption could cause an erroneous result when trying to check for a repeat of the original character. 13. Some tidying changes to the testing mechanism: (a) The RunTest script now detects the internal link size and whether there is UTF-8 and UCP support by running ./pcretest -C instead of relying on values substituted by "configure". (The RunGrepTest script already did this for UTF-8.) The configure.ac script no longer substitutes the relevant variables. (b) The debugging options /B and /D in pcretest show the compiled bytecode with length and offset values. This means that the output is different for different internal link sizes. Test 2 is skipped for link sizes other than 2 because of this, bypassing the problem. Unfortunately, there was also a test in test 3 (the locale tests) that used /B and failed for link sizes other than 2. Rather than cut the whole test out, I have added a new /Z option to pcretest that replaces the length and offset values with spaces. This is now used to make test 3 independent of link size. (Test 2 will be tidied up later.) 14. If erroroffset was passed as NULL to pcre_compile, it provoked a segmentation fault instead of returning the appropriate error message. 15. In multiline mode when the newline sequence was set to "any", the pattern ^$ would give a match between the \r and \n of a subject such as "A\r\nB". This doesn't seem right; it now treats the CRLF combination as the line ending, and so does not match in that case. It's only a pattern such as ^$ that would hit this one: something like ^ABC$ would have failed after \r and then tried again after \r\n. 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub" in an attempt to make files that differ only in their line terminators compare equal. This works on Linux. 17. Under certain error circumstances pcregrep might try to free random memory as it exited. This is now fixed, thanks to valgrind. 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string "abc\r\n\r\n", it found an unwanted second match after the second \r. This was because its rules for how to advance for /g after matching an empty string at the end of a line did not allow for this case. They now check for it specially. 20. pcretest is supposed to handle patterns and data of any length, by extending its buffers when necessary. It was getting this wrong when the buffer for a data line had to be extended. 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or CRLF as a newline sequence. 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but I have nevertheless tidied it up. 23. Added some casts to kill warnings from HP-UX ia64 compiler. 24. Added a man page for pcre-config. Version 7.0 19-Dec-06 --------------------- 1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by moving to gcc 4.1.1. 2. The -S option for pcretest uses setrlimit(); I had omitted to #include sys/time.h, which is documented as needed for this function. It doesn't seem to matter on Linux, but it showed up on some releases of OS X. 3. It seems that there are systems where bytes whose values are greater than 127 match isprint() in the "C" locale. The "C" locale should be the default when a C program starts up. In most systems, only ASCII printing characters match isprint(). This difference caused the output from pcretest to vary, making some of the tests fail. I have changed pcretest so that: (a) When it is outputting text in the compiled version of a pattern, bytes other than 32-126 are always shown as hex escapes. (b) When it is outputting text that is a matched part of a subject string, it does the same, unless a different locale has been set for the match (using the /L modifier). In this case, it uses isprint() to decide. 4. Fixed a major bug that caused incorrect computation of the amount of memory required for a compiled pattern when options that changed within the pattern affected the logic of the preliminary scan that determines the length. The relevant options are -x, and -i in UTF-8 mode. The result was that the computed length was too small. The symptoms of this bug were either the PCRE error "internal error: code overflow" from pcre_compile(), or a glibc crash with a message such as "pcretest: free(): invalid next size (fast)". Examples of patterns that provoked this bug (shown in pcretest format) are: /(?-x: )/x /(?x)(?-x: \s*#\s*)/ /((?i)[\x{c0}])/8 /(?i:[\x{c0}])/8 HOWEVER: Change 17 below makes this fix obsolete as the memory computation is now done differently. 5. Applied patches from Google to: (a) add a QuoteMeta function to the C++ wrapper classes; (b) implement a new function in the C++ scanner that is more efficient than the old way of doing things because it avoids levels of recursion in the regex matching; (c) add a paragraph to the documentation for the FullMatch() function. 6. The escape sequence \n was being treated as whatever was defined as "newline". Not only was this contrary to the documentation, which states that \n is character 10 (hex 0A), but it also went horribly wrong when "newline" was defined as CRLF. This has been fixed. 7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c) was being set to -1 for the "end of line" case (supposedly a value that no character can have). Though this value is never used (the check for end of line is "zero bytes in current character"), it caused compiler complaints. I've changed it to 0xffffffff. 8. In pcre_version.c, the version string was being built by a sequence of C macros that, in the event of PCRE_PRERELEASE being defined as an empty string (as it is for production releases) called a macro with an empty argument. The C standard says the result of this is undefined. The gcc compiler treats it as an empty string (which was what was wanted) but it is reported that Visual C gives an error. The source has been hacked around to avoid this problem. 9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows builds of pcretest, and changed the call to _setmode() to use _O_BINARY instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all of them did). 10. Originally, pcretest opened its input and output without "b"; then I was told that "b" was needed in some environments, so it was added for release 5.0 to both the input and output. (It makes no difference on Unix-like systems.) Later I was told that it is wrong for the input on Windows. I've now abstracted the modes into two macros, to make it easier to fiddle with them, and removed "b" from the input mode under Windows. 11. Added pkgconfig support for the C++ wrapper library, libpcrecpp. 12. Added -help and --help to pcretest as an official way of being reminded of the options. 13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in and pcrecpp.cc because they annoy compilers at high warning levels. 14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop. 15. Fixed an occurrence of == in configure.ac that should have been = (shell scripts are not C programs :-) and which was not noticed because it works on Linux. 16. pcretest is supposed to handle any length of pattern and data line (as one line or as a continued sequence of lines) by extending its input buffer if necessary. This feature was broken for very long pattern lines, leading to a string of junk being passed to pcre_compile() if the pattern was longer than about 50K. 17. I have done a major re-factoring of the way pcre_compile() computes the amount of memory needed for a compiled pattern. Previously, there was code that made a preliminary scan of the pattern in order to do this. That was OK when PCRE was new, but as the facilities have expanded, it has become harder and harder to keep it in step with the real compile phase, and there have been a number of bugs (see for example, 4 above). I have now found a cunning way of running the real compile function in a "fake" mode that enables it to compute how much memory it would need, while actually only ever using a few hundred bytes of working memory and without too many tests of the mode. This should make future maintenance and development easier. A side effect of this work is that the limit of 200 on the nesting depth of parentheses has been removed (though this was never a serious limitation, I suspect). However, there is a downside: pcre_compile() now runs more slowly than before (30% or more, depending on the pattern). I hope this isn't a big issue. There is no effect on runtime performance. 18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a newline (only possible for the last line of a file) and it was a pattern that set a locale (followed by /Lsomething), pcretest crashed. 19. Added additional timing features to pcretest. (1) The -tm option now times matching only, not compiling. (2) Both -t and -tm can be followed, as a separate command line item, by a number that specifies the number of repeats to use when timing. The default is 50000; this gives better precision, but takes uncomfortably long for very large patterns. 20. Extended pcre_study() to be more clever in cases where a branch of a subpattern has no definite first character. For example, (a*|b*)[cd] would previously give no result from pcre_study(). Now it recognizes that the first character must be a, b, c, or d. 21. There was an incorrect error "recursive call could loop indefinitely" if a subpattern (or the entire pattern) that was being tested for matching an empty string contained only one non-empty item after a nested subpattern. For example, the pattern (?>\x{100}*)\d(?R) provoked this error incorrectly, because the \d was being skipped in the check. 22. The pcretest program now has a new pattern option /B and a command line option -b, which is equivalent to adding /B to every pattern. This causes it to show the compiled bytecode, without the additional information that -d shows. The effect of -d is now the same as -b with -i (and similarly, /D is the same as /B/I). 23. A new optimization is now able automatically to treat some sequences such as a*b as a*+b. More specifically, if something simple (such as a character or a simple class like \d) has an unlimited quantifier, and is followed by something that cannot possibly match the quantified thing, the quantifier is automatically "possessified". 24. A recursive reference to a subpattern whose number was greater than 39 went wrong under certain circumstances in UTF-8 mode. This bug could also have affected the operation of pcre_study(). 25. Realized that a little bit of performance could be had by replacing (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters. 26. Timing data from pcretest is now shown to 4 decimal places instead of 3. 27. Possessive quantifiers such as a++ were previously implemented by turning them into atomic groups such as ($>a+). Now they have their own opcodes, which improves performance. This includes the automatically created ones from 23 above. 28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a lookahead was broken if it was not anchored. PCRE was mistakenly expecting the first matched character to be a colon. This applied both to named and numbered groups. 29. The ucpinternal.h header file was missing its idempotency #ifdef. 30. I was sent a "project" file called libpcre.a.dev which I understand makes building PCRE on Windows easier, so I have included it in the distribution. 31. There is now a check in pcretest against a ridiculously large number being returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G loop, the loop is abandoned. 32. Forward references to subpatterns in conditions such as (?(2)...) where subpattern 2 is defined later cause pcre_compile() to search forwards in the pattern for the relevant set of parentheses. This search went wrong when there were unescaped parentheses in a character class, parentheses escaped with \Q...\E, or parentheses in a #-comment in /x mode. 33. "Subroutine" calls and backreferences were previously restricted to referencing subpatterns earlier in the regex. This restriction has now been removed. 34. Added a number of extra features that are going to be in Perl 5.10. On the whole, these are just syntactic alternatives for features that PCRE had previously implemented using the Python syntax or my own invention. The other formats are all retained for compatibility. (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well as (?P<name>...). The new forms, as well as being in Perl 5.10, are also .NET compatible. (b) A recursion or subroutine call to a named group can now be defined as (?&name) as well as (?P>name). (c) A backreference to a named group can now be defined as \k<name> or \k'name' as well as (?P=name). The new forms, as well as being in Perl 5.10, are also .NET compatible. (d) A conditional reference to a named group can now use the syntax (?(<name>) or (?('name') as well as (?(name). (e) A "conditional group" of the form (?(DEFINE)...) can be used to define groups (named and numbered) that are never evaluated inline, but can be called as "subroutines" from elsewhere. In effect, the DEFINE condition is always false. There may be only one alternative in such a group. (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well as the simple (?(R). The condition is true only if the most recent recursion is that of the given number or name. It does not search out through the entire recursion stack. (g) The escape \gN or \g{N} has been added, where N is a positive or negative number, specifying an absolute or relative reference. 35. Tidied to get rid of some further signed/unsigned compiler warnings and some "unreachable code" warnings. 36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other things, this adds five new scripts. 37. Perl ignores orphaned \E escapes completely. PCRE now does the same. There were also incompatibilities regarding the handling of \Q..\E inside character classes, for example with patterns like [\Qa\E-\Qz\E] where the hyphen was adjacent to \Q or \E. I hope I've cleared all this up now. 38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group matches an empty string, and forcibly breaks the loop. There were bugs in this code in non-simple cases. For a pattern such as ^(a()*)* matched against aaaa the result was just "a" rather than "aaaa", for example. Two separate and independent bugs (that affected different cases) have been fixed. 39. Refactored the code to abolish the use of different opcodes for small capturing bracket numbers. This is a tidy that I avoided doing when I removed the limit on the number of capturing brackets for 3.5 back in 2001. The new approach is not only tidier, it makes it possible to reduce the memory needed to fix the previous bug (38). 40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when processing dot, circumflex, or dollar metacharacters, or #-comments in /x mode. 41. Add \R to match any Unicode newline sequence, as suggested in the Unicode report. 42. Applied patch, originally from Ari Pollak, modified by Google, to allow copy construction and assignment in the C++ wrapper. 43. Updated pcregrep to support "--newline=any". In the process, I fixed a couple of bugs that could have given wrong results in the "--newline=crlf" case. 44. Added a number of casts and did some reorganization of signed/unsigned int variables following suggestions from Dair Grant. Also renamed the variable "this" as "item" because it is a C++ keyword. 45. Arranged for dftables to add #include "pcre_internal.h" to pcre_chartables.c because without it, gcc 4.x may remove the array definition from the final binary if PCRE is built into a static library and dead code stripping is activated. 46. For an unanchored pattern, if a match attempt fails at the start of a newline sequence, and the newline setting is CRLF or ANY, and the next two characters are CRLF, advance by two characters instead of one. Version 6.7 04-Jul-06 --------------------- 1. In order to handle tests when input lines are enormously long, pcretest has been re-factored so that it automatically extends its buffers when necessary. The code is crude, but this _is_ just a test program. The default size has been increased from 32K to 50K. 2. The code in pcre_study() was using the value of the re argument before testing it for NULL. (Of course, in any sensible call of the function, it won't be NULL.) 3. The memmove() emulation function in pcre_internal.h, which is used on systems that lack both memmove() and bcopy() - that is, hardly ever - was missing a "static" storage class specifier. 4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns containing an extended class (one that cannot be represented by a bitmap because it contains high-valued characters or Unicode property items, e.g. [\pZ]). Almost always one would set UTF-8 mode when processing such a pattern, but PCRE should not loop if you do not (it no longer does). [Detail: two cases were found: (a) a repeated subpattern containing an extended class; (b) a recursive reference to a subpattern that followed a previous extended class. It wasn't skipping over the extended class correctly when UTF-8 mode was not set.] 5. A negated single-character class was not being recognized as fixed-length in lookbehind assertions such as (?<=[^f]), leading to an incorrect compile error "lookbehind assertion is not fixed length". 6. The RunPerlTest auxiliary script was showing an unexpected difference between PCRE and Perl for UTF-8 tests. It turns out that it is hard to write a Perl script that can interpret lines of an input file either as byte characters or as UTF-8, which is what "perltest" was being required to do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you can't do is switch easily at run time between having the "use utf8;" pragma or not. In the end, I fudged it by using the RunPerlTest script to insert "use utf8;" explicitly for the UTF-8 tests. 7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at the end of the subject string, contrary to the documentation and to what Perl does. This was true of both matching functions. Now it matches only at the start of the subject and immediately after *internal* newlines. 8. A call of pcre_fullinfo() from pcretest to get the option bits was passing a pointer to an int instead of a pointer to an unsigned long int. This caused problems on 64-bit systems. 9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another instance of the 'standard' template library not being so standard". 10. There was no check on the number of named subpatterns nor the maximum length of a subpattern name. The product of these values is used to compute the size of the memory block for a compiled pattern. By supplying a very long subpattern name and a large number of named subpatterns, the size computation could be caused to overflow. This is now prevented by limiting the length of names to 32 characters, and the number of named subpatterns to 10,000. 11. Subpatterns that are repeated with specific counts have to be replicated in the compiled pattern. The size of memory for this was computed from the length of the subpattern and the repeat count. The latter is limited to 65535, but there was no limit on the former, meaning that integer overflow could in principle occur. The compiled length of a repeated subpattern is now limited to 30,000 bytes in order to prevent this. 12. Added the optional facility to have named substrings with the same name. 13. Added the ability to use a named substring as a condition, using the Python syntax: (?(name)yes|no). This overloads (?(R)... and names that are numbers (not recommended). Forward references are permitted. 14. Added forward references in named backreferences (if you see what I mean). 15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the pattern could run off the end of the subject. For example, the pattern "(?s)(.{1,5})"8 did this with the subject "ab". 16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if PCRE_CASELESS was set when matching characters that were quantified with ? or *. 17. A character class other than a single negated character that had a minimum but no maximum quantifier - for example [ab]{6,} - was not handled correctly by pce_dfa_exec(). It would match only one character. 18. A valid (though odd) pattern that looked like a POSIX character class but used an invalid character after [ (for example [[,abc,]]) caused pcre_compile() to give the error "Failed: internal error: code overflow" or in some cases to crash with a glibc free() error. This could even happen if the pattern terminated after [[ but there just happened to be a sequence of letters, a binary zero, and a closing ] in the memory that followed. 19. Perl's treatment of octal escapes in the range \400 to \777 has changed over the years. Originally (before any Unicode support), just the bottom 8 bits were taken. Thus, for example, \500 really meant \100. Nowadays the output from "man perlunicode" includes this: The regular expression compiler produces polymorphic opcodes. That is, the pattern adapts to the data and automatically switches to the Unicode character scheme when presented with Unicode data--or instead uses a traditional byte scheme when presented with byte data. Sadly, a wide octal escape does not cause a switch, and in a string with no other multibyte characters, these octal escapes are treated as before. Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a Unicode string. I have not perpetrated such confusion in PCRE. Up till now, it took just the bottom 8 bits, as in old Perl. I have now made octal escapes with values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they translate to the appropriate multibyte character. 29. Applied some refactoring to reduce the number of warnings from Microsoft and Borland compilers. This has included removing the fudge introduced seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused a warning about an unused variable. 21. PCRE has not included VT (character 0x0b) in the set of whitespace characters since release 4.0, because Perl (from release 5.004) does not. [Or at least, is documented not to: some releases seem to be in conflict with the documentation.] However, when a pattern was studied with pcre_study() and all its branches started with \s, PCRE still included VT as a possible starting character. Of course, this did no harm; it just caused an unnecessary match attempt. 22. Removed a now-redundant internal flag bit that recorded the fact that case dependency changed within the pattern. This was once needed for "required byte" processing, but is no longer used. This recovers a now-scarce options bit. Also moved the least significant internal flag bit to the most- significant bit of the word, which was not previously used (hangover from the days when it was an int rather than a uint) to free up another bit for the future. 23. Added support for CRLF line endings as well as CR and LF. As well as the default being selectable at build time, it can now be changed at runtime via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to specify that it is scanning data with non-default line endings. 24. Changed the definition of CXXLINK to make it agree with the definition of LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS. 25. Applied Ian Taylor's patches to avoid using another stack frame for tail recursions. This makes a big different to stack usage for some patterns. 26. If a subpattern containing a named recursion or subroutine reference such as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of the space required for the compiled pattern went wrong and gave too small a value. Depending on the environment, this could lead to "Failed: internal error: code overflow at offset 49" or "glibc detected double free or corruption" errors. 27. Applied patches from Google (a) to support the new newline modes and (b) to advance over multibyte UTF-8 characters in GlobalReplace. 28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a difference for some implementation of PCRE in some Windows version. 29. Added some extra testing facilities to pcretest: \q<number> in a data line sets the "match limit" value \Q<number> in a data line sets the "match recursion limt" value -S <number> sets the stack size, where <number> is in megabytes The -S option isn't available for Windows. Version 6.6 06-Feb-06 --------------------- 1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined in pcreposix.h. I have copied the definition from pcre.h. 2. Change 25 for 6.5 broke compilation in a build directory out-of-tree because pcre.h is no longer a built file. 3. Added Jeff Friedl's additional debugging patches to pcregrep. These are not normally included in the compiled code. Version 6.5 01-Feb-06 --------------------- 1. When using the partial match feature with pcre_dfa_exec(), it was not anchoring the second and subsequent partial matches at the new starting point. This could lead to incorrect results. For example, with the pattern /1234/, partially matching against "123" and then "a4" gave a match. 2. Changes to pcregrep: (a) All non-match returns from pcre_exec() were being treated as failures to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an error message is output. Some extra information is given for the PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are probably the only errors that are likely to be caused by users (by specifying a regex that has nested indefinite repeats, for instance). If there are more than 20 of these errors, pcregrep is abandoned. (b) A binary zero was treated as data while matching, but terminated the output line if it was written out. This has been fixed: binary zeroes are now no different to any other data bytes. (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is used to set a locale for matching. The --locale=xxxx long option has been added (no short equivalent) to specify a locale explicitly on the pcregrep command, overriding the environment variables. (d) When -B was used with -n, some line numbers in the output were one less than they should have been. (e) Added the -o (--only-matching) option. (f) If -A or -C was used with -c (count only), some lines of context were accidentally printed for the final match. (g) Added the -H (--with-filename) option. (h) The combination of options -rh failed to suppress file names for files that were found from directory arguments. (i) Added the -D (--devices) and -d (--directories) options. (j) Added the -F (--fixed-strings) option. (k) Allow "-" to be used as a file name for -f as well as for a data file. (l) Added the --colo(u)r option. (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it is not present by default. 3. A nasty bug was discovered in the handling of recursive patterns, that is, items such as (?R) or (?1), when the recursion could match a number of alternatives. If it matched one of the alternatives, but subsequently, outside the recursion, there was a failure, the code tried to back up into the recursion. However, because of the way PCRE is implemented, this is not possible, and the result was an incorrect result from the match. In order to prevent this happening, the specification of recursion has been changed so that all such subpatterns are automatically treated as atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)). 4. I had overlooked the fact that, in some locales, there are characters for which isalpha() is true but neither isupper() nor islower() are true. In the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine and ordfeminine) are like this. This affected the treatment of \w and \W when they appeared in character classes, but not when they appeared outside a character class. The bit map for "word" characters is now created separately from the results of isalnum() instead of just taking it from the upper, lower, and digit maps. (Plus the underscore character, of course.) 5. The above bug also affected the handling of POSIX character classes such as [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's permanent tables. Instead, the bit maps for such a class were previously created as the appropriate unions of the upper, lower, and digit bitmaps. Now they are created by subtraction from the [[:word:]] class, which has its own bitmap. 6. The [[:blank:]] character class matches horizontal, but not vertical space. It is created by subtracting the vertical space characters (\x09, \x0a, \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the subtraction was done in the overall bitmap for a character class, meaning that a class such as [\x0c[:blank:]] was incorrect because \x0c would not be recognized. This bug has been fixed. 7. Patches from the folks at Google: (a) pcrecpp.cc: "to handle a corner case that may or may not happen in real life, but is still worth protecting against". (b) pcrecpp.cc: "corrects a bug when negative radixes are used with regular expressions". (c) pcre_scanner.cc: avoid use of std::count() because not all systems have it. (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by "configure" and the latter not, in order to fix a problem somebody had with compiling the Arg class on HP-UX. (e) Improve the error-handling of the C++ wrapper a little bit. (f) New tests for checking recursion limiting. 8. The pcre_memmove() function, which is used only if the environment does not have a standard memmove() function (and is therefore rarely compiled), contained two bugs: (a) use of int instead of size_t, and (b) it was not returning a result (though PCRE never actually uses the result). 9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is returned instead of calling malloc() with an overflowing number that would most likely cause subsequent chaos. 10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag. 11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled with this option is matched, the nmatch and pmatch options of regexec() are ignored. 12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is provided in case anyone wants to the the POSIX interface with UTF-8 strings. 13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the C++ linking (needed for some HP-UX environments). 14. Avoid compiler warnings in get_ucpname() when compiled without UCP support (unused parameter) and in the pcre_printint() function (omitted "default" switch label when the default is to do nothing). 15. Added some code to make it possible, when PCRE is compiled as a C++ library, to replace subject pointers for pcre_exec() with a smart pointer class, thus making it possible to process discontinuous strings. 16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform much the same function. They were added by different people who were trying to make PCRE easy to compile on non-Unix systems. It has been suggested that PCRE_EXPORT be abolished now that there is more automatic apparatus for compiling on Windows systems. I have therefore replaced it with PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it defaults to "extern" for C or "extern C" for C++, which works fine on Unix-like systems. It is now possible to override the value of PCRE_DATA_ SCOPE with something explicit in config.h. In addition: (a) pcreposix.h still had just "extern" instead of either of these macros; I have replaced it with PCRE_DATA_SCOPE. (b) Functions such as _pcre_xclass(), which are internal to the library, but external in the C sense, all had PCRE_EXPORT in their definitions. This is apparently wrong for the Windows case, so I have removed it. (It makes no difference on Unix-like systems.) 17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting of recursive calls to match(). This is different to MATCH_LIMIT because that limits the total number of calls to match(), not all of which increase the depth of recursion. Limiting the recursion depth limits the amount of stack (or heap if NO_RECURSE is set) that is used. The default can be set when PCRE is compiled, and changed at run time. A patch from Google adds this functionality to the C++ interface. 18. Changes to the handling of Unicode character properties: (a) Updated the table to Unicode 4.1.0. (b) Recognize characters that are not in the table as "Cn" (undefined). (c) I revised the way the table is implemented to a much improved format which includes recognition of ranges. It now supports the ranges that are defined in UnicodeData.txt, and it also amalgamates other characters into ranges. This has reduced the number of entries in the table from around 16,000 to around 3,000, thus reducing its size considerably. I realized I did not need to use a tree structure after all - a binary chop search is just as efficient. Having reduced the number of entries, I extended their size from 6 bytes to 8 bytes to allow for more data. (d) Added support for Unicode script names via properties such as \p{Han}. 19. In UTF-8 mode, a backslash followed by a non-Ascii character was not matching that character. 20. When matching a repeated Unicode property with a minimum greater than zero, (for example \pL{2,}), PCRE could look past the end of the subject if it reached it while seeking the minimum number of characters. This could happen only if some of the characters were more than one byte long, because there is a check for at least the minimum number of bytes. 21. Refactored the implementation of \p and \P so as to be more general, to allow for more different types of property in future. This has changed the compiled form incompatibly. Anybody with saved compiled patterns that use \p or \P will have to recompile them. 22. Added "Any" and "L&" to the supported property types. 23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode, but give a compile time error if the value is greater than 0xff. 24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were accidentally not being installed or uninstalled. 25. The pcre.h file was built from pcre.h.in, but the only changes that were made were to insert the current release number. This seemed silly, because it made things harder for people building PCRE on systems that don't run "configure". I have turned pcre.h into a distributed file, no longer built by "configure", with the version identification directly included. There is no longer a pcre.h.in file. However, this change necessitated a change to the pcre-config script as well. It is built from pcre-config.in, and one of the substitutions was the release number. I have updated configure.ac so that ./configure now finds the release number by grepping pcre.h. 26. Added the ability to run the tests under valgrind. Version 6.4 05-Sep-05 --------------------- 1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines "--" to be printed when multiple files were scanned, even when none of the -A, -B, or -C options were used. This is not compatible with Gnu grep, so I consider it to be a bug, and have restored the previous behaviour. 2. A couple of code tidies to get rid of compiler warnings. 3. The pcretest program used to cheat by referring to symbols in the library whose names begin with _pcre_. These are internal symbols that are not really supposed to be visible externally, and in some environments it is possible to suppress them. The cheating is now confined to including certain files from the library's source, which is a bit cleaner. 4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the file's purpose clearer. 5. Reorganized pcre_ucp_findchar(). Version 6.3 15-Aug-05 --------------------- 1. The file libpcre.pc.in did not have general read permission in the tarball. 2. There were some problems when building without C++ support: (a) If C++ support was not built, "make install" and "make test" still tried to test it. (b) There were problems when the value of CXX was explicitly set. Some changes have been made to try to fix these, and ... (c) --disable-cpp can now be used to explicitly disable C++ support. (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a backslash in a target when C++ was disabled. This confuses some versions of "make", apparently. Using an intermediate variable solves this. (Same for CPP_LOBJ.) 3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK) (non-Windows) now includes $(CFLAGS) because these flags are sometimes necessary on certain architectures. 4. Added a setting of -export-symbols-regex to the link command to remove those symbols that are exported in the C sense, but actually are local within the library, and not documented. Their names all begin with "_pcre_". This is not a perfect job, because (a) we have to except some symbols that pcretest ("illegally") uses, and (b) the facility isn't always available (and never for static libraries). I have made a note to try to find a way round (a) in the future. Version 6.2 01-Aug-05 --------------------- 1. There was no test for integer overflow of quantifier values. A construction such as {1111111111111111} would give undefined results. What is worse, if a minimum quantifier for a parenthesized subpattern overflowed and became negative, the calculation of the memory size went wrong. This could have led to memory overwriting. 2. Building PCRE using VPATH was broken. Hopefully it is now fixed. 3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like operating environments where this matters. 4. Applied Giuseppe Maxia's patch to add additional features for controlling PCRE options from within the C++ wrapper. 5. Named capturing subpatterns were not being correctly counted when a pattern was compiled. This caused two problems: (a) If there were more than 100 such subpatterns, the calculation of the memory needed for the whole compiled pattern went wrong, leading to an overflow error. (b) Numerical back references of the form \12, where the number was greater than 9, were not recognized as back references, even though there were sufficient previous subpatterns. 6. Two minor patches to pcrecpp.cc in order to allow it to compile on older versions of gcc, e.g. 2.95.4. Version 6.1 21-Jun-05 --------------------- 1. There was one reference to the variable "posix" in pcretest.c that was not surrounded by "#if !defined NOPOSIX". 2. Make it possible to compile pcretest without DFA support, UTF8 support, or the cross-check on the old pcre_info() function, for the benefit of the cut-down version of PCRE that is currently imported into Exim. 3. A (silly) pattern starting with (?i)(?-i) caused an internal space allocation error. I've done the easy fix, which wastes 2 bytes for sensible patterns that start (?i) but I don't think that matters. The use of (?i) is just an example; this all applies to the other options as well. 4. Since libtool seems to echo the compile commands it is issuing, the output from "make" can be reduced a bit by putting "@" in front of each libtool compile command. 5. Patch from the folks at Google for configure.in to be a bit more thorough in checking for a suitable C++ installation before trying to compile the C++ stuff. This should fix a reported problem when a compiler was present, but no suitable headers. 6. The man pages all had just "PCRE" as their title. I have changed them to be the relevant file name. I have also arranged that these names are retained in the file doc/pcre.txt, which is a concatenation in text format of all the man pages except the little individual ones for each function. 7. The NON-UNIX-USE file had not been updated for the different set of source files that come with release 6. I also added a few comments about the C++ wrapper. Version 6.0 07-Jun-05 --------------------- 1. Some minor internal re-organization to help with my DFA experiments. 2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that didn't matter for the library itself when fully configured, but did matter when compiling without UCP support, or within Exim, where the ucp files are not imported. 3. Refactoring of the library code to split up the various functions into different source modules. The addition of the new DFA matching code (see below) to a single monolithic source would have made it really too unwieldy, quite apart from causing all the code to be include in a statically linked application, when only some functions are used. This is relevant even without the DFA addition now that patterns can be compiled in one application and matched in another. The downside of splitting up is that there have to be some external functions and data tables that are used internally in different modules of the library but which are not part of the API. These have all had their names changed to start with "_pcre_" so that they are unlikely to clash with other external names. 4. Added an alternate matching function, pcre_dfa_exec(), which matches using a different (DFA) algorithm. Although it is slower than the original function, it does have some advantages for certain types of matching problem. 5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(), including restarting after a partial match. 6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not defined when compiling for Windows was sent to me. I have put it into the code, though I have no means of testing or verifying it. 7. Added the pcre_refcount() auxiliary function. 8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to match before or at the first newline in the subject string. In pcretest, the /f option on a pattern can be used to set this. 9. A repeated \w when used in UTF-8 mode with characters greater than 256 would behave wrongly. This has been present in PCRE since release 4.0. 10. A number of changes to the pcregrep command: (a) Refactored how -x works; insert ^(...)$ instead of setting PCRE_ANCHORED and checking the length, in preparation for adding something similar for -w. (b) Added the -w (match as a word) option. (c) Refactored the way lines are read and buffered so as to have more than one at a time available. (d) Implemented a pcregrep test script. (e) Added the -M (multiline match) option. This allows patterns to match over several lines of the subject. The buffering ensures that at least 8K, or the rest of the document (whichever is the shorter) is available for matching (and similarly the previous 8K for lookbehind assertions). (f) Changed the --help output so that it now says -w, --word-regex(p) instead of two lines, one with "regex" and the other with "regexp" because that confused at least one person since the short forms are the same. (This required a bit of code, as the output is generated automatically from a table. It wasn't just a text change.) (g) -- can be used to terminate pcregrep options if the next thing isn't an option but starts with a hyphen. Could be a pattern or a path name starting with a hyphen, for instance. (h) "-" can be given as a file name to represent stdin. (i) When file names are being printed, "(standard input)" is used for the standard input, for compatibility with GNU grep. Previously "<stdin>" was used. (j) The option --label=xxx can be used to supply a name to be used for stdin when file names are being printed. There is no short form. (k) Re-factored the options decoding logic because we are going to add two more options that take data. Such options can now be given in four different ways, e.g. "-fname", "-f name", "--file=name", "--file name". (l) Added the -A, -B, and -C options for requesting that lines of context around matches be printed. (m) Added the -L option to print the names of files that do not contain any matching lines, that is, the complement of -l. (n) The return code is 2 if any file cannot be opened, but pcregrep does continue to scan other files. (o) The -s option was incorrectly implemented. For compatibility with other greps, it now suppresses the error message for a non-existent or non- accessible file (but not the return code). There is a new option called -q that suppresses the output of matching lines, which was what -s was previously doing. (p) Added --include and --exclude options to specify files for inclusion and exclusion when recursing. 11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly. Hopefully, it now does. 12. Missing cast in pcre_study(). 13. Added an "uninstall" target to the makefile. 14. Replaced "extern" in the function prototypes in Makefile.in with "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix world, but is set differently for Windows. 15. Added a second compiling function called pcre_compile2(). The only difference is that it has an extra argument, which is a pointer to an integer error code. When there is a compile-time failure, this is set non-zero, in addition to the error test pointer being set to point to an error message. The new argument may be NULL if no error number is required (but then you may as well call pcre_compile(), which is now just a wrapper). This facility is provided because some applications need a numeric error indication, but it has also enabled me to tidy up the way compile-time errors are handled in the POSIX wrapper. 16. Added VPATH=.libs to the makefile; this should help when building with one prefix path and installing with another. (Or so I'm told by someone who knows more about this stuff than I do.) 17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This passes PCRE_DOTALL to the pcre_compile() function, making the "." character match everything, including newlines. This is not POSIX-compatible, but somebody wanted the feature. From pcretest it can be activated by using both the P and the s flags. 18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one. 19. libpcre.pc was being incorrectly installed as executable. 20. A couple of places in pcretest check for end-of-line by looking for '\n'; it now also looks for '\r' so that it will work unmodified on Windows. 21. Added Google's contributed C++ wrapper to the distribution. 22. Added some untidy missing memory free() calls in pcretest, to keep Electric Fence happy when testing. Version 5.0 13-Sep-04 --------------------- 1. Internal change: literal characters are no longer packed up into items containing multiple characters in a single byte-string. Each character is now matched using a separate opcode. However, there may be more than one byte in the character in UTF-8 mode. 2. The pcre_callout_block structure has two new fields: pattern_position and next_item_length. These contain the offset in the pattern to the next match item, and its length, respectively. 3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic insertion of callouts before each pattern item. Added the /C option to pcretest to make use of this. 4. On the advice of a Windows user, the lines #if defined(_WIN32) || defined(WIN32) _setmode( _fileno( stdout ), 0x8000 ); #endif /* defined(_WIN32) || defined(WIN32) */ have been added to the source of pcretest. This apparently does useful magic in relation to line terminators. 5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb" for the benefit of those environments where the "b" makes a difference. 6. The icc compiler has the same options as gcc, but "configure" doesn't seem to know about it. I have put a hack into configure.in that adds in code to set GCC=yes if CC=icc. This seems to end up at a point in the generated configure script that is early enough to affect the setting of compiler options, which is what is needed, but I have no means of testing whether it really works. (The user who reported this had patched the generated configure script, which of course I cannot do.) LATER: After change 22 below (new libtool files), the configure script seems to know about icc (and also ecc). Therefore, I have commented out this hack in configure.in. 7. Added support for pkg-config (2 patches were sent in). 8. Negated POSIX character classes that used a combination of internal tables were completely broken. These were [[:^alpha:]], [[:^alnum:]], and [[:^ascii]]. Typically, they would match almost any characters. The other POSIX classes were not broken in this way. 9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed to find the match, as PCRE was deluded into thinking that the match had to start at the start point or following a newline. The same bug applied to patterns with negative forward assertions or any backward assertions preceding ".*" at the start, unless the pattern required a fixed first character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed. 10. In UTF-8 mode, when moving forwards in the subject after a failed match starting at the last subject character, bytes beyond the end of the subject string were read. 11. Renamed the variable "class" as "classbits" to make life easier for C++ users. (Previously there was a macro definition, but it apparently wasn't enough.) 12. Added the new field "tables" to the extra data so that tables can be passed in at exec time, or the internal tables can be re-selected. This allows a compiled regex to be saved and re-used at a later time by a different program that might have everything at different addresses. 13. Modified the pcre-config script so that, when run on Solaris, it shows a -R library as well as a -L library. 14. The debugging options of pcretest (-d on the command line or D on a pattern) showed incorrect output for anything following an extended class that contained multibyte characters and which was followed by a quantifier. 15. Added optional support for general category Unicode character properties via the \p, \P, and \X escapes. Unicode property support implies UTF-8 support. It adds about 90K to the size of the library. The meanings of the inbuilt class escapes such as \d and \s have NOT been changed. 16. Updated pcredemo.c to include calls to free() to release the memory for the compiled pattern. 17. The generated file chartables.c was being created in the source directory instead of in the building directory. This caused the build to fail if the source directory was different from the building directory, and was read-only. 18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE file. No doubt somebody will tell me if they don't make sense... Also added Dan Mooney's comments about building on OpenVMS. 19. Added support for partial matching via the PCRE_PARTIAL option for pcre_exec() and the \P data escape in pcretest. 20. Extended pcretest with 3 new pattern features: (i) A pattern option of the form ">rest-of-line" causes pcretest to write the compiled pattern to the file whose name is "rest-of-line". This is a straight binary dump of the data, with the saved pointer to the character tables forced to be NULL. The study data, if any, is written too. After writing, pcretest reads a new pattern. (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a compiled pattern from the given file. There must not be any occurrences of "<" in the file name (pretty unlikely); if there are, pcretest will instead treat the initial "<" as a pattern delimiter. After reading in the pattern, pcretest goes on to read data lines as usual. (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit and 16-bit fields in a compiled pattern, to simulate a pattern that was compiled on a host of opposite endianness. 21. The pcre-exec() function can now cope with patterns that were compiled on hosts of opposite endianness, with this restriction: As for any compiled expression that is saved and used later, the tables pointer field cannot be preserved; the extra_data field in the arguments to pcre_exec() should be used to pass in a tables address if a value other than the default internal tables were used at compile time. 22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is now diagnosed as an error. Previously, most of the time, a negative number would have been treated as zero, but if in addition "ovector" was passed as NULL, a crash could occur. 23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with new versions from the libtool 1.5 distribution (the last one is a copy of a file called libtool.m4). This seems to have fixed the need to patch "configure" to support Darwin 1.3 (which I used to do). However, I still had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my workstation). 24. Changed the PCRE licence to be the more standard "BSD" licence. Version 4.5 01-Dec-03 --------------------- 1. There has been some re-arrangement of the code for the match() function so that it can be compiled in a version that does not call itself recursively. Instead, it keeps those local variables that need separate instances for each "recursion" in a frame on the heap, and gets/frees frames whenever it needs to "recurse". Keeping track of where control must go is done by means of setjmp/longjmp. The whole thing is implemented by a set of macros that hide most of the details from the main code, and operates only if NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the "configure" mechanism, "--disable-stack-for-recursion" turns on this way of operating. To make it easier for callers to provide specially tailored get/free functions for this usage, two new functions, pcre_stack_malloc, and pcre_stack_free, are used. They are always called in strict stacking order, and the size of block requested is always the same. The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether PCRE has been compiled to use the stack or the heap for recursion. The -C option of pcretest uses this to show which version is compiled. A new data escape \S, is added to pcretest; it causes the amounts of store obtained and freed by both kinds of malloc/free at match time to be added to the output. 2. Changed the locale test to use "fr_FR" instead of "fr" because that's what's available on my current Linux desktop machine. 3. When matching a UTF-8 string, the test for a valid string at the start has been extended. If start_offset is not zero, PCRE now checks that it points to a byte that is the start of a UTF-8 character. If not, it returns PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked; this is necessary because there may be backward assertions in the pattern. When matching the same subject several times, it may save resources to use PCRE_NO_UTF8_CHECK on all but the first call if the string is long. 4. The code for checking the validity of UTF-8 strings has been tightened so that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings containing "overlong sequences". 5. Fixed a bug (appearing twice) that I could not find any way of exploiting! I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&" should have been "&", but it just so happened that all the cases this let through by mistake were picked up later in the function. 6. I had used a variable called "isblank" - this is a C99 function, causing some compilers to warn. To avoid this, I renamed it (as "blankclass"). 7. Cosmetic: (a) only output another newline at the end of pcretest if it is prompting; (b) run "./pcretest /dev/null" at the start of the test script so the version is shown; (c) stop "make test" echoing "./RunTest". 8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems. 9. The prototype for memmove() for systems that don't have it was using size_t, but the inclusion of the header that defines size_t was later. I've moved the #includes for the C headers earlier to avoid this. 10. Added some adjustments to the code to make it easier to compiler on certain special systems: (a) Some "const" qualifiers were missing. (b) Added the macro EXPORT before all exported functions; by default this is defined to be empty. (c) Changed the dftables auxiliary program (that builds chartables.c) so that it reads its output file name as an argument instead of writing to the standard output and assuming this can be redirected. 11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character class containing characters with values greater than 255, PCRE compilation went into a loop. 12. A recursive reference to a subpattern that was within another subpattern that had a minimum quantifier of zero caused PCRE to crash. For example, (x(y(?2))z)? provoked this bug with a subject that got as far as the recursion. If the recursively-called subpattern itself had a zero repeat, that was OK. 13. In pcretest, the buffer for reading a data line was set at 30K, but the buffer into which it was copied (for escape processing) was still set at 1024, so long lines caused crashes. 14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error "internal error: code overflow...". This applied to any character class that was followed by a possessive quantifier. 15. Modified the Makefile to add libpcre.la as a prerequisite for libpcreposix.la because I was told this is needed for a parallel build to work. 16. If a pattern that contained .* following optional items at the start was studied, the wrong optimizing data was generated, leading to matching errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any matching string must start with a or b or c. The correct conclusion for this pattern is that a match can start with any character. Version 4.4 13-Aug-03 --------------------- 1. In UTF-8 mode, a character class containing characters with values between 127 and 255 was not handled correctly if the compiled pattern was studied. In fixing this, I have also improved the studying algorithm for such classes (slightly). 2. Three internal functions had redundant arguments passed to them. Removal might give a very teeny performance improvement. 3. Documentation bug: the value of the capture_top field in a callout is *one more than* the number of the hightest numbered captured substring. 4. The Makefile linked pcretest and pcregrep with -lpcre, which could result in incorrectly linking with a previously installed version. They now link explicitly with libpcre.la. 5. configure.in no longer needs to recognize Cygwin specially. 6. A problem in pcre.in for Windows platforms is fixed. 7. If a pattern was successfully studied, and the -d (or /D) flag was given to pcretest, it used to include the size of the study block as part of its output. Unfortunately, the structure contains a field that has a different size on different hardware architectures. This meant that the tests that showed this size failed. As the block is currently always of a fixed size, this information isn't actually particularly useful in pcretest output, so I have just removed it. 8. Three pre-processor statements accidentally did not start in column 1. Sadly, there are *still* compilers around that complain, even though standard C has not required this for well over a decade. Sigh. 9. In pcretest, the code for checking callouts passed small integers in the callout_data field, which is a void * field. However, some picky compilers complained about the casts involved for this on 64-bit systems. Now pcretest passes the address of the small integer instead, which should get rid of the warnings. 10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at both compile and run time, and gives an error if an invalid UTF-8 sequence is found. There is a option for disabling this check in cases where the string is known to be correct and/or the maximum performance is wanted. 11. In response to a bug report, I changed one line in Makefile.in from -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \ to -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \ to look similar to other lines, but I have no way of telling whether this is the right thing to do, as I do not use Windows. No doubt I'll get told if it's wrong... Version 4.3 21-May-03 --------------------- 1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the Makefile. 2. Some refactoring to improve the quality of the code: (i) The utf8_table... variables are now declared "const". (ii) The code for \cx, which used the "case flipping" table to upper case lower case letters, now just substracts 32. This is ASCII-specific, but the whole concept of \cx is ASCII-specific, so it seems reasonable. (iii) PCRE was using its character types table to recognize decimal and hexadecimal digits in the pattern. This is silly, because it handles only 0-9, a-f, and A-F, but the character types table is locale- specific, which means strange things might happen. A private table is now used for this - though it costs 256 bytes, a table is much faster than multiple explicit tests. Of course, the standard character types table is still used for matching digits in subject strings against \d. (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers ending in _t are). So I've renamed it as ESC_tee. 3. The first argument for regexec() in the POSIX wrapper should have been defined as "const". 4. Changed pcretest to use malloc() for its buffers so that they can be Electric Fenced for debugging. 5. There were several places in the code where, in UTF-8 mode, PCRE would try to read one or more bytes before the start of the subject string. Often this had no effect on PCRE's behaviour, but in some circumstances it could provoke a segmentation fault. 6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE to try to read one or more bytes before the start of the subject string. 7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with UTF-8 support could misbehave in various ways if the subject string contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind area. (PCRE was not checking for the UTF-8 mode flag, and trying to move back over UTF-8 characters.) Version 4.2 14-Apr-03 --------------------- 1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed. 2. Changes to the building process, supplied by Ronald Landheer-Cieslak [ON_WINDOWS]: new variable, "#" on non-Windows platforms [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms [WIN_PREFIX]: new variable, "cyg" for Cygwin * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT and BUILD_EXEEXT Note: automatic setting of the BUILD variables is not yet working set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at compile-time but not at link-time [LINK]: use for linking executables only make different versions for Windows and non-Windows [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking libraries [LINK_FOR_BUILD]: new variable [OBJEXT]: use throughout [EXEEXT]: use throughout <winshared>: new target <wininstall>: new target <dftables.o>: use native compiler <dftables>: use native linker <install>: handle Windows platform correctly <clean>: ditto <check>: ditto copy DLL to top builddir before testing As part of these changes, -no-undefined was removed again. This was reported to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea in any case. 3. Some tidies to get rid of compiler warnings: . In the match_data structure, match_limit was an unsigned long int, whereas match_call_count was an int. I've made them both unsigned long ints. . In pcretest the fact that a const uschar * doesn't automatically cast to a void * provoked a warning. . Turning on some more compiler warnings threw up some "shadow" variables and a few more missing casts. 4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8 option, a class that contained a single character with a value between 128 and 255 (e.g. /[\xFF]/) caused PCRE to crash. 5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8 option, a class that contained several characters, but with at least one whose value was between 128 and 255 caused PCRE to crash. Version 4.1 12-Mar-03 --------------------- 1. Compiling with gcc -pedantic found a couple of places where casts were needed, and a string in dftables.c that was longer than standard compilers are required to support. 2. Compiling with Sun's compiler found a few more places where the code could be tidied up in order to avoid warnings. 3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the first of these names is deprecated in the latest Autoconf in favour of the name CC_FOR_BUILD, because "host" is typically used to mean the system on which the compiled code will be run. I can't find a reference for HOST_CFLAGS, but by analogy I have changed it to CFLAGS_FOR_BUILD. 4. Added -no-undefined to the linking command in the Makefile, because this is apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the linking step for the pcreposix library. 5. PCRE was failing to diagnose the case of two named groups with the same name. 6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a literal character that is needed in the subject for a match, and scans along to ensure that it is present before embarking on the full matching process. This saves time in cases of nested unlimited repeats that are never going to match. Problem: the scan can take a lot of time if the subject is very long (e.g. megabytes), thus penalizing straightforward matches. It is now done only if the amount of subject to be scanned is less than 1000 bytes. 7. A lesser problem with the same optimization is that it was recording the first character of an anchored pattern as "needed", thus provoking a search right along the subject, even when the first match of the pattern was going to fail. The "needed" character is now not set for anchored patterns, unless it follows something in the pattern that is of non-fixed length. Thus, it still fulfils its original purpose of finding quick non-matches in cases of nested unlimited repeats, but isn't used for simple anchored patterns such as /^abc/. Version 4.0 17-Feb-03 --------------------- 1. If a comment in an extended regex that started immediately after a meta-item extended to the end of string, PCRE compiled incorrect data. This could lead to all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not. 2. Moved to autoconf 2.53 and libtool 1.4.2. 3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently, the special perltest8 script is no longer needed - all the tests can be run from a single perltest script. 4. From 5.004, Perl has not included the VT character (0x0b) in the set defined by \s. It has now been removed in PCRE. This means it isn't recognized as whitespace in /x regexes too, which is the same as Perl. Note that the POSIX class [:space:] *does* include VT, thereby creating a mess. 5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only space and tab. 6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use its new features into the main test script, reducing the number of scripts. 7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions were backward compatible, and made the (?i) apply to the whole pattern, as if /i were given. Now it behaves more logically, and applies the option setting only to what follows. PCRE has been changed to follow suit. However, if it finds options settings right at the start of the pattern, it extracts them into the global options, as before. Thus, they show up in the info data. 8. Added support for the \Q...\E escape sequence. Characters in between are treated as literals. This is slightly different from Perl in that $ and @ are also handled as literals inside the quotes. In Perl, they will cause variable interpolation. Note the following examples: Pattern PCRE matches Perl matches \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz \Qabc\$xyz\E abc\$xyz abc\$xyz \Qabc\E\$\Qxyz\E abc$xyz abc$xyz For compatibility with Perl, \Q...\E sequences are recognized inside character classes as well as outside them. 9. Re-organized 3 code statements in pcretest to avoid "overflow in floating-point constant arithmetic" warnings from a Microsoft compiler. Added a (size_t) cast to one statement in pcretest and one in pcreposix to avoid signed/unsigned warnings. 10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o option for pcretest, so I've replaced it by a simple function that does just that job. 11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or "pcregrep -". 12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's Java package. This provides some syntactic sugar for simple cases of what my documentation calls "once-only subpatterns". A pattern such as x*+ is the same as (?>x*). In other words, if what is inside (?>...) is just a single repeated item, you can use this simplified notation. Note that only makes sense with greedy quantifiers. Consequently, the use of the possessive quantifier forces greediness, whatever the setting of the PCRE_UNGREEDY option. 13. A change of greediness default within a pattern was not taking effect at the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option was abstracted outside. 14. PCRE now supports the \G assertion. It is true when the current matching position is at the start point of the match. This differs from \A when the starting offset is non-zero. Used with the /g option of pcretest (or similar code), it works in the same way as it does for Perl's /g option. If all alternatives of a regex begin with \G, the expression is anchored to the start match position, and the "anchored" flag is set in the compiled expression. 15. Some bugs concerning the handling of certain option changes within patterns have been fixed. These applied to options other than (?ims). For example, "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have been the other way round. Some of this was related to change 7 above. 16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/ and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports POSIX classes only within a class (e.g. /[[:alpha:]]/). 17. Added support for Perl's \C escape. This matches one byte, even in UTF8 mode. Unlike ".", it always matches newline, whatever the setting of PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind assertions. Perl allows it, but it doesn't (in general) work because it can't calculate the length of the lookbehind. At least, that's the case for Perl 5.8.0 - I've been told they are going to document that it doesn't work in future. 18. Added an error diagnosis for escapes that PCRE does not support: these are \L, \l, \N, \P, \p, \U, \u, and \X. 19. Although correctly diagnosing a missing ']' in a character class, PCRE was reading past the end of the pattern in cases such as /[abcd/. 20. PCRE was getting more memory than necessary for patterns with classes that contained both POSIX named classes and other characters, e.g. /[[:space:]abc/. 21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for compiling PCRE for use with Virtual Pascal. 22. Small fix to the Makefile to make it work properly if the build is done outside the source tree. 23. Added a new extension: a condition to go with recursion. If a conditional subpattern starts with (?(R) the "true" branch is used if recursion has happened, whereas the "false" branch is used only at the top level. 24. When there was a very long string of literal characters (over 255 bytes without UTF support, over 250 bytes with UTF support), the computation of how much memory was required could be incorrect, leading to segfaults or other strange effects. 25. PCRE was incorrectly assuming anchoring (either to start of subject or to start of line for a non-DOTALL pattern) when a pattern started with (.*) and there was a subsequent back reference to those brackets. This meant that, for example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't possible to check for precisely this case. All we can do is abandon the optimization if .* occurs inside capturing brackets when there are any back references whatsoever. (See below for a better fix that came later.) 26. The handling of the optimization for finding the first character of a non-anchored pattern, and for finding a character that is required later in the match were failing in some cases. This didn't break the matching; it just failed to optimize when it could. The way this is done has been re-implemented. 27. Fixed typo in error message for invalid (?R item (it said "(?p"). 28. Added a new feature that provides some of the functionality that Perl provides with (?{...}). The facility is termed a "callout". The way it is done in PCRE is for the caller to provide an optional function, by setting pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a global variable. By default it is unset, which disables all calling out. To get the function called, the regex must include (?C) at appropriate points. This is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C). This provides a means of identifying different callout points. When PCRE reaches such a point in the regex, if pcre_callout has been set, the external function is called. It is provided with data in a structure called pcre_callout_block, which is defined in pcre.h. If the function returns 0, matching continues; if it returns a non-zero value, the match at the current point fails. However, backtracking will occur if possible. [This was changed later and other features added - see item 49 below.] 29. pcretest is upgraded to test the callout functionality. It provides a callout function that displays information. By default, it shows the start of the match and the current position in the text. There are some new data escapes to vary what happens: \C+ in addition, show current contents of captured substrings \C- do not supply a callout function \C!n return 1 when callout number n is reached \C!n!m return 1 when callout number n is reached for the mth time 30. If pcregrep was called with the -l option and just a single file name, it output "<stdin>" if a match was found, instead of the file name. 31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to pcre_exec(). This saves a malloc/free per call. The default value of POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold when configuring. 32. The default maximum size of a compiled pattern is 64K. There have been a few cases of people hitting this limit. The code now uses macros to handle the storing of links as offsets within the compiled pattern. It defaults to 2-byte links, but this can be changed to 3 or 4 bytes by --with-link-size when configuring. Tests 2 and 5 work only with 2-byte links because they output debugging information about compiled patterns. 33. Internal code re-arrangements: (a) Moved the debugging function for printing out a compiled regex into its own source file (printint.c) and used #include to pull it into pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two separate copies. (b) Defined the list of op-code names for debugging as a macro in internal.h so that it is next to the definition of the opcodes. (c) Defined a table of op-code lengths for simpler skipping along compiled code. This is again a macro in internal.h so that it is next to the definition of the opcodes. 34. Added support for recursive calls to individual subpatterns, along the lines of Robin Houston's patch (but implemented somewhat differently). 35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to allow it to read and process whole directories in Win32. This code was contributed by Lionel Fourquaux; it has not been tested by me. 36. Added support for named subpatterns. The Python syntax (?P<name>...) is used to name a group. Names consist of alphanumerics and underscores, and must be unique. Back references use the syntax (?P=name) and recursive calls use (?P>name) which is a PCRE extension to the Python extension. Groups still have numbers. The function pcre_fullinfo() can be used after compilation to extract a name/number map. There are three relevant calls: PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map PCRE_INFO_NAMECOUNT yields the number of entries PCRE_INFO_NAMETABLE yields a pointer to the map. The map is a vector of fixed-size entries. The size of each entry depends on the length of the longest name used. The first two bytes of each entry are the group number, most significant byte first. There follows the corresponding name, zero terminated. The names are in alphabetical order. 37. Make the maximum literal string in the compiled code 250 for the non-UTF-8 case instead of 255. Making it the same both with and without UTF-8 support means that the same test output works with both. 38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid calling malloc() with a zero argument. 39. Change 25 above had to resort to a heavy-handed test for the .* anchoring optimization. I've improved things by keeping a bitmap of backreferences with numbers 1-31 so that if .* occurs inside capturing brackets that are not in fact referenced, the optimization can be applied. It is unlikely that a relevant occurrence of .* (i.e. one which might indicate anchoring or forcing the match to follow \n) will appear inside brackets with a number greater than 31, but if it does, any back reference > 31 suppresses the optimization. 40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect of disabling numbered capturing parentheses. Any opening parenthesis that is not followed by ? behaves as if it were followed by ?: but named parentheses can still be used for capturing (and they will acquire numbers in the usual way). 41. Redesigned the return codes from the match() function into yes/no/error so that errors can be passed back from deep inside the nested calls. A malloc failure while inside a recursive subpattern call now causes the PCRE_ERROR_NOMEMORY return instead of quietly going wrong. 42. It is now possible to set a limit on the number of times the match() function is called in a call to pcre_exec(). This facility makes it possible to limit the amount of recursion and backtracking, though not in a directly obvious way, because the match() function is used in a number of different circumstances. The count starts from zero for each position in the subject string (for non-anchored patterns). The default limit is, for compatibility, a large number, namely 10 000 000. You can change this in two ways: (a) When configuring PCRE before making, you can use --with-match-limit=n to set a default value for the compiled library. (b) For each call to pcre_exec(), you can pass a pcre_extra block in which a different value is set. See 45 below. If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT. 43. Added a new function pcre_config(int, void *) to enable run-time extraction of things that can be changed at compile time. The first argument specifies what is wanted and the second points to where the information is to be placed. The current list of available information is: PCRE_CONFIG_UTF8 The output is an integer that is set to one if UTF-8 support is available; otherwise it is set to zero. PCRE_CONFIG_NEWLINE The output is an integer that it set to the value of the code that is used for newline. It is either LF (10) or CR (13). PCRE_CONFIG_LINK_SIZE The output is an integer that contains the number of bytes used for internal linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above. PCRE_CONFIG_POSIX_MALLOC_THRESHOLD The output is an integer that contains the threshold above which the POSIX interface uses malloc() for output vectors. See item 31 above. PCRE_CONFIG_MATCH_LIMIT The output is an unsigned integer that contains the default limit of the number of match() calls in a pcre_exec() execution. See 42 above. 44. pcretest has been upgraded by the addition of the -C option. This causes it to extract all the available output from the new pcre_config() function, and to output it. The program then exits immediately. 45. A need has arisen to pass over additional data with calls to pcre_exec() in order to support additional features. One way would have been to define pcre_exec2() (for example) with extra arguments, but this would not have been extensible, and would also have required all calls to the original function to be mapped to the new one. Instead, I have chosen to extend the mechanism that is used for passing in "extra" data from pcre_study(). The pcre_extra structure is now exposed and defined in pcre.h. It currently contains the following fields: flags a bitmap indicating which of the following fields are set study_data opaque data from pcre_study() match_limit a way of specifying a limit on match() calls for a specific call to pcre_exec() callout_data data for callouts (see 49 below) The flag bits are also defined in pcre.h, and are PCRE_EXTRA_STUDY_DATA PCRE_EXTRA_MATCH_LIMIT PCRE_EXTRA_CALLOUT_DATA The pcre_study() function now returns one of these new pcre_extra blocks, with the actual study data pointed to by the study_data field, and the PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as before. That is, this change is entirely upwards-compatible and requires no change to existing code. If you want to pass in additional data to pcre_exec(), you can either place it in a pcre_extra block provided by pcre_study(), or create your own pcre_extra block. 46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a data string contains the escape sequence \M, pcretest calls pcre_exec() several times with different match limits, until it finds the minimum value needed for pcre_exec() to complete. The value is then output. This can be instructive; for most simple matches the number is quite small, but for pathological cases it gets very large very quickly. 47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It returns the size of the data block pointed to by the study_data field in a pcre_extra block, that is, the value that was passed as the argument to pcre_malloc() when PCRE was getting memory in which to place the information created by pcre_study(). The fourth argument should point to a size_t variable. pcretest has been extended so that this information is shown after a successful pcre_study() call when information about the compiled regex is being displayed. 48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR) because what follows is always an absolute path. (Later: it turns out that this is more than cosmetic for MinGW, because it doesn't like empty path components.) 49. Some changes have been made to the callout feature (see 28 above): (i) A callout function now has three choices for what it returns: 0 => success, carry on matching > 0 => failure at this point, but backtrack if possible < 0 => serious error, return this value from pcre_exec() Negative values should normally be chosen from the set of PCRE_ERROR_xxx values. In particular, returning PCRE_ERROR_NOMATCH forces a standard "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for use by callout functions. It will never be used by PCRE itself. (ii) The pcre_extra structure (see 45 above) has a void * field called callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The pcre_callout_block structure has a field of the same name. The contents of the field passed in the pcre_extra structure are passed to the callout function in the corresponding field in the callout block. This makes it easier to use the same callout-containing regex from multiple threads. For testing, the pcretest program has a new data escape \C*n pass the number n (may be negative) as callout_data If the callout function in pcretest receives a non-zero value as callout_data, it returns that value. 50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also, there were some redundant $(CFLAGS) in commands that are now specified as $(LINK), which already includes $(CFLAGS). 51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE has been compiled with UTF-8 support *and* pcre_compile() has been compiled with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume one-byte characters throughout. Note that case-insensitive matching applies only to characters whose values are less than 256. PCRE doesn't support the notion of cases for higher-valued characters. (i) A character class whose characters are all within 0-255 is handled as a bit map, and the map is inverted for negative classes. Previously, a character > 255 always failed to match such a class; however it should match if the class was a negative one (e.g. [^ab]). This has been fixed. (ii) A negated character class with a single character < 255 is coded as "not this character" (OP_NOT). This wasn't working properly when the test character was multibyte, either singly or repeated. (iii) Repeats of multibyte characters are now handled correctly in UTF-8 mode, for example: \x{100}{2,3}. (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either singly or repeated) now correctly test multibyte characters. However, PCRE doesn't recognize any characters with values greater than 255 as digits, spaces, or word characters. Such characters always match \D, \S, and \W, and never match \d, \s, or \w. (v) Classes may now contain characters and character ranges with values greater than 255. For example: [ab\x{100}-\x{400}]. (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call PCRE in UTF-8 mode. 52. The info request value PCRE_INFO_FIRSTCHAR has been renamed PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is retained for backwards compatibility. (Note that LASTLITERAL is also a byte value.) 53. The single man page has become too large. I have therefore split it up into a number of separate man pages. These also give rise to individual HTML pages; these are now put in a separate directory, and there is an index.html page that lists them all. Some hyperlinking between the pages has been installed. 54. Added convenience functions for handling named capturing parentheses. 55. Unknown escapes inside character classes (e.g. [\M]) and escapes that aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also true in PCRE, except when the PCRE_EXTENDED option is set, in which case they are faulted. 56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when calling configure. These values are used when compiling the dftables.c program which is run to generate the source of the default character tables. They default to the values of CC and CFLAGS. If you are cross-compiling PCRE, you will need to set these values. 57. Updated the building process for Windows DLL, as provided by Fred Cox. Version 3.9 02-Jan-02 --------------------- 1. A bit of extraneous text had somehow crept into the pcregrep documentation. 2. If --disable-static was given, the building process failed when trying to build pcretest and pcregrep. (For some reason it was using libtool to compile them, which is not right, as they aren't part of the library.) Version 3.8 18-Dec-01 --------------------- 1. The experimental UTF-8 code was completely screwed up. It was packing the bytes in the wrong order. How dumb can you get? Version 3.7 29-Oct-01 --------------------- 1. In updating pcretest to check change 1 of version 3.6, I screwed up. This caused pcretest, when used on the test data, to segfault. Unfortunately, this didn't happen under Solaris 8, where I normally test things. 2. The Makefile had to be changed to make it work on BSD systems, where 'make' doesn't seem to recognize that ./xxx and xxx are the same file. (This entry isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made this fix an hour or so after the initial 3.7 release.) Version 3.6 23-Oct-01 --------------------- 1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if offsets passed as NULL with zero offset count. 2. The config.guess and config.sub files had not been updated when I moved to the latest autoconf. Version 3.5 15-Aug-01 --------------------- 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that had been forgotten. 2. By using declared but undefined structures, we can avoid using "void" definitions in pcre.h while keeping the internal definitions of the structures private. 3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a user point of view, this means that both static and shared libraries are built by default, but this can be individually controlled. More of the work of handling this static/shared cases is now inside libtool instead of PCRE's make file. 4. The pcretest utility is now installed along with pcregrep because it is useful for users (to test regexs) and by doing this, it automatically gets relinked by libtool. The documentation has been turned into a man page, so there are now .1, .txt, and .html versions in /doc. 5. Upgrades to pcregrep: (i) Added long-form option names like gnu grep. (ii) Added --help to list all options with an explanatory phrase. (iii) Added -r, --recursive to recurse into sub-directories. (iv) Added -f, --file to read patterns from a file. 6. pcre_exec() was referring to its "code" argument before testing that argument for NULL (and giving an error if it was NULL). 7. Upgraded Makefile.in to allow for compiling in a different directory from the source directory. 8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the options bits, the pointer it was passed was to an int instead of to an unsigned long int. This mattered only on 64-bit systems. 9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is generated) instead of pcre.in, which it its source. Also made the same change in several of the .c files. 10. A new release of gcc defines printf() as a macro, which broke pcretest because it had an ifdef in the middle of a string argument for printf(). Fixed by using separate calls to printf(). 11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure script, to force use of CR or LF instead of \n in the source. On non-Unix systems, the value can be set in config.h. 12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an absolute limit. Changed the text of the error message to make this clear, and likewise updated the man page. 13. The limit of 99 on the number of capturing subpatterns has been removed. The new limit is 65535, which I hope will not be a "real" limit. Version 3.4 22-Aug-00 --------------------- 1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *. 2. Diagnose condition (?(0) as an error instead of crashing on matching. Version 3.3 01-Aug-00 --------------------- 1. If an octal character was given, but the value was greater than \377, it was not getting masked to the least significant bits, as documented. This could lead to crashes in some systems. 2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats the hyphen as a literal. PCRE used to give an error; it now behaves like Perl. 3. Added the functions pcre_free_substring() and pcre_free_substring_list(). These just pass their arguments on to (pcre_free)(), but they are provided because some uses of PCRE bind it to non-C systems that can call its functions, but cannot call free() or pcre_free() directly. 4. Add "make test" as a synonym for "make check". Corrected some comments in the Makefile. 5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the Makefile. 6. Changed the name of pgrep to pcregrep, because Solaris has introduced a command called pgrep for grepping around the active processes. 7. Added the beginnings of support for UTF-8 character strings. 8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and RANLIB to ./ltconfig so that they are used by libtool. I think these are all the relevant ones. (AR is not passed because ./ltconfig does its own figuring out for the ar command.) Version 3.2 12-May-00 --------------------- This is purely a bug fixing release. 1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead of ZA. This was just one example of several cases that could provoke this bug, which was introduced by change 9 of version 2.00. The code for breaking infinite loops after an iteration that matches an empty string was't working correctly. 2. The pcretest program was not imitating Perl correctly for the pattern /a*/g when matched against abbab (for example). After matching an empty string, it wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this caused it to match further down the string than it should. 3. The code contained an inclusion of sys/types.h. It isn't clear why this was there because it doesn't seem to be needed, and it causes trouble on some systems, as it is not a Standard C header. It has been removed. 4. Made 4 silly changes to the source to avoid stupid compiler warnings that were reported on the Macintosh. The changes were from while ((c = *(++ptr)) != 0 && c != '\n'); to while ((c = *(++ptr)) != 0 && c != '\n') ; Totally extraordinary, but if that's what it takes... 5. PCRE is being used in one environment where neither memmove() nor bcopy() is available. Added HAVE_BCOPY and an autoconf test for it; if neither HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which assumes the way PCRE uses memmove() (always moving upwards). 6. PCRE is being used in one environment where strchr() is not available. There was only one use in pcre.c, and writing it out to avoid strchr() probably gives faster code anyway. Version 3.1 09-Feb-00 --------------------- The only change in this release is the fixing of some bugs in Makefile.in for the "install" target: (1) It was failing to install pcreposix.h. (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page. Version 3.0 01-Feb-00 --------------------- 1. Add support for the /+ modifier to perltest (to output $` like it does in pcretest). 2. Add support for the /g modifier to perltest. 3. Fix pcretest so that it behaves even more like Perl for /g when the pattern matches null strings. 4. Fix perltest so that it doesn't do unwanted things when fed an empty pattern. Perl treats empty patterns specially - it reuses the most recent pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this effect. 5. The POSIX interface was broken in that it was just handing over the POSIX captured string vector to pcre_exec(), but (since release 2.00) PCRE has required a bigger vector, with some working space on the end. This means that the POSIX wrapper now has to get and free some memory, and copy the results. 6. Added some simple autoconf support, placing the test data and the documentation in separate directories, re-organizing some of the information files, and making it build pcre-config (a GNU standard). Also added libtool support for building PCRE as a shared library, which is now the default. 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and 09 are not valid octal constants. Single digits will be used for minor values less than 10. 8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that existing programs that set these in the POSIX interface can use PCRE without modification. 9. Added a new function, pcre_fullinfo() with an extensible interface. It can return all that pcre_info() returns, plus additional data. The pcre_info() function is retained for compatibility, but is considered to be obsolete. 10. Added experimental recursion feature (?R) to handle one common case that Perl 5.6 will be able to do with (?p{...}). 11. Added support for POSIX character classes like [:alpha:], which Perl is adopting. Version 2.08 31-Aug-99 ---------------------- 1. When startoffset was not zero and the pattern began with ".*", PCRE was not trying to match at the startoffset position, but instead was moving forward to the next newline as if a previous match had failed. 2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G, and could get into a loop if a null string was matched other than at the start of the subject. 3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can be distinguished at compile time, and for completeness also added PCRE_DATE. 5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL in GnuWin32 environments. Version 2.07 29-Jul-99 ---------------------- 1. The documentation is now supplied in plain text form and HTML as well as in the form of man page sources. 2. C++ compilers don't like assigning (void *) values to other pointer types. In particular this affects malloc(). Although there is no problem in Standard C, I've put in casts to keep C++ compilers happy. 3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call should be (const char *). 4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may be useful for non-Unix systems who don't want to bother with the POSIX stuff. However, I haven't made this a standard facility. The documentation doesn't mention it, and the Makefile doesn't support it. 5. The Makefile now contains an "install" target, with editable destinations at the top of the file. The pcretest program is not installed. 6. pgrep -V now gives the PCRE version number and date. 7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was causing the entire string to be ignored, instead of just the last character. 8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a non-matching string, it can take a very, very long time, even for strings of quite modest length, because of the nested recursion. PCRE now does better in some of these cases. It does this by remembering the last required literal character in the pattern, and pre-searching the subject to ensure it is present before running the real match. In other words, it applies a heuristic to detect some types of certain failure quickly, and in the above example, if presented with a string that has no trailing " it gives "no match" very quickly. 9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored; other alternatives are tried instead. Version 2.06 09-Jun-99 ---------------------- 1. Change pcretest's output for amount of store used to show just the code space, because the remainder (the data block) varies in size between 32-bit and 64-bit systems. 2. Added an extra argument to pcre_exec() to supply an offset in the subject to start matching at. This allows lookbehinds to work when searching for multiple occurrences in a string. 3. Added additional options to pcretest for testing multiple occurrences: /+ outputs the rest of the string that follows a match /g loops for multiple occurrences, using the new startoffset argument /G loops for multiple occurrences by passing an incremented pointer 4. PCRE wasn't doing the "first character" optimization for patterns starting with \b or \B, though it was doing it for other lookbehind assertions. That is, it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with the letter 'x'. On long subject strings, this gives a significant speed-up. Version 2.05 21-Apr-99 ---------------------- 1. Changed the type of magic_number from int to long int so that it works properly on 16-bit systems. 2. Fixed a bug which caused patterns starting with .* not to work correctly when the subject string contained newline characters. PCRE was assuming anchoring for such patterns in all cases, which is not correct because .* will not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if DOTALL is set at top level; otherwise it knows that patterns starting with .* must be retried after every newline in the subject. Version 2.04 18-Feb-99 ---------------------- 1. For parenthesized subpatterns with repeats whose minimum was zero, the computation of the store needed to hold the pattern was incorrect (too large). If such patterns were nested a few deep, this could multiply and become a real problem. 2. Added /M option to pcretest to show the memory requirement of a specific pattern. Made -m a synonym of -s (which does this globally) for compatibility. 3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being compiled in such a way that the backtracking after subsequent failure was pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size. Version 2.03 02-Feb-99 ---------------------- 1. Fixed typo and small mistake in man page. 2. Added 4th condition (GPL supersedes if conflict) and created separate LICENCE file containing the conditions. 3. Updated pcretest so that patterns such as /abc\/def/ work like they do in Perl, that is the internal \ allows the delimiter to be included in the pattern. Locked out the use of \ as a delimiter. If \ immediately follows the final delimiter, add \ to the end of the pattern (to test the error). 4. Added the convenience functions for extracting substrings after a successful match. Updated pcretest to make it able to test these functions. Version 2.02 14-Jan-99 ---------------------- 1. Initialized the working variables associated with each extraction so that their saving and restoring doesn't refer to uninitialized store. 2. Put dummy code into study.c in order to trick the optimizer of the IBM C compiler for OS/2 into generating correct code. Apparently IBM isn't going to fix the problem. 3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution calls, and wasn't printing the correct value for compiling calls. Increased the default value of LOOPREPEAT, and the number of significant figures in the times. 4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT. 5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid a building problem on Windows NT with a FAT file system. Version 2.01 21-Oct-98 ---------------------- 1. Changed the API for pcre_compile() to allow for the provision of a pointer to character tables built by pcre_maketables() in the current locale. If NULL is passed, the default tables are used. Version 2.00 24-Sep-98 ---------------------- 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable it any more. 2. Allow quantification of (?>) groups, and make it work correctly. 3. The first character computation wasn't working for (?>) groups. 4. Correct the implementation of \Z (it is permitted to match on the \n at the end of the subject) and add 5.005's \z, which really does match only at the very end of the subject. 5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater. 6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005 localized options. All options to pcre_study() were also removed. 7. Add other new features from 5.005: $(?<= positive lookbehind $(?<! negative lookbehind (?imsx-imsx) added the unsetting capability such a setting is global if at outer level; local otherwise (?imsx-imsx:) non-capturing groups with option setting (?(cond)re|re) conditional pattern matching A backreference to itself in a repeated group matches the previous captured string. 8. General tidying up of studying (both automatic and via "study") consequential on the addition of new assertions. 9. As in 5.005, unlimited repeated groups that could match an empty substring are no longer faulted at compile time. Instead, the loop is forcibly broken at runtime if any iteration does actually match an empty substring. 10. Include the RunTest script in the distribution. 11. Added tests from the Perl 5.005_02 distribution. This showed up a few discrepancies, some of which were old and were also with respect to 5.004. They have now been fixed. Version 1.09 28-Apr-98 ---------------------- 1. A negated single character class followed by a quantifier with a minimum value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to program crashes, or just wrong answers. This did not apply to negated classes containing more than one character, or to minima other than one. Version 1.08 27-Mar-98 ---------------------- 1. Add PCRE_UNGREEDY to invert the greediness of quantifiers. 2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The latter must appear before anything that relies on it in the pattern. Version 1.07 16-Feb-98 ---------------------- 1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited repeat of a potentially empty string). Version 1.06 23-Jan-98 ---------------------- 1. Added Markus Oberhumer's little patches for C++. 2. Literal strings longer than 255 characters were broken. Version 1.05 23-Dec-97 ---------------------- 1. Negated character classes containing more than one character were failing if PCRE_CASELESS was set at run time. Version 1.04 19-Dec-97 ---------------------- 1. Corrected the man page, where some "const" qualifiers had been omitted. 2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with input syntax. 3. Fixed memory leak which occurred when a regex with back references was matched with an offsets vector that wasn't big enough. The temporary memory that is used in this case wasn't being freed if the match failed. 4. Tidied pcretest to ensure it frees memory that it gets. 5. Temporary memory was being obtained in the case where the passed offsets vector was exactly big enough. 6. Corrected definition of offsetof() from change 5 below. 7. I had screwed up change 6 below and broken the rules for the use of setjmp(). Now fixed. Version 1.03 18-Dec-97 ---------------------- 1. A erroneous regex with a missing opening parenthesis was correctly diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes on some systems. 2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because it was reported that one broken compiler failed on the former because "code" is also an independent variable. 3. The erroneous regex a[]b caused an array overrun reference. 4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not fail on data ending with that character. (It was going on too far, and checking the next character, typically a binary zero.) This was specific to the optimized code for single-character negative classes. 5. Added a contributed patch from the TIN world which does the following: + Add an undef for memmove, in case the the system defines a macro for it. + Add a definition of offsetof(), in case there isn't one. (I don't know the reason behind this - offsetof() is part of the ANSI standard - but it does no harm). + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating most of the places where whitespace preceded '#'. I have given up and allowed the remaining 2 cases to be at the margin. + Rename some variables in pcre to eliminate shadowing. This seems very pedantic, but does no harm, of course. 6. Moved the call to setjmp() into its own function, to get rid of warnings from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used. 7. Constructs such as \d{8,} were compiling into the equivalent of \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the outcome, but in this particular case used more store than had been allocated, which caused the bug to be discovered because it threw up an internal error. 8. The debugging code in both pcre and pcretest for outputting the compiled form of a regex was going wrong in the case of back references followed by curly-bracketed repeats. Version 1.02 12-Dec-97 ---------------------- 1. Typos in pcre.3 and comments in the source fixed. 2. Applied a contributed patch to get rid of places where it used to remove 'const' from variables, and fixed some signed/unsigned and uninitialized variable warnings. 3. Added the "runtest" target to Makefile. 4. Set default compiler flag to -O2 rather than just -O. Version 1.01 19-Nov-97 ---------------------- 1. PCRE was failing to diagnose unlimited repeat of empty string for patterns like /([ab]*)*/, that is, for classes with more than one character in them. 2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such as /((?>a*))*/ (a PCRE_EXTRA facility). Version 1.00 18-Nov-97 ---------------------- 1. Added compile-time macros to support systems such as SunOS4 which don't have memmove() or strerror() but have other things that can be used instead. 2. Arranged that "make clean" removes the executables. Version 0.99 27-Oct-97 ---------------------- 1. Fixed bug in code for optimizing classes with only one character. It was initializing a 32-byte map regardless, which could cause it to run off the end of the memory it had got. 2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction. Version 0.98 22-Oct-97 ---------------------- 1. Fixed bug in code for handling temporary memory usage when there are more back references than supplied space in the ovector. This could cause segfaults. Version 0.97 21-Oct-97 ---------------------- 1. Added the \X "cut" facility, conditional on PCRE_EXTRA. 2. Optimized negated single characters not to use a bit map. 3. Brought error texts together as macro definitions; clarified some of them; fixed one that was wrong - it said "range out of order" when it meant "invalid escape sequence". 4. Changed some char * arguments to const char *. 5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX). 6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in pcretest. Version 0.96 16-Oct-97 ---------------------- 1. Added a simple "pgrep" utility to the distribution. 2. Fixed an incompatibility with Perl: "{" is now treated as a normal character unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}" where "ddd" means "one or more decimal digits". 3. Fixed serious bug. If a pattern had a back reference, but the call to pcre_exec() didn't supply a large enough ovector to record the related identifying subpattern, the match always failed. PCRE now remembers the number of the largest back reference, and gets some temporary memory in which to save the offsets during matching if necessary, in order to ensure that backreferences always work. 4. Increased the compatibility with Perl in a number of ways: (a) . no longer matches \n by default; an option PCRE_DOTALL is provided to request this handling. The option can be set at compile or exec time. (b) $ matches before a terminating newline by default; an option PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline mode). The option can be set at compile or exec time. (c) The handling of \ followed by a digit other than 0 is now supposed to be the same as Perl's. If the decimal number it represents is less than 10 or there aren't that many previous left capturing parentheses, an octal escape is read. Inside a character class, it's always an octal escape, even if it is a single digit. (d) An escaped but undefined alphabetic character is taken as a literal, unless PCRE_EXTRA is set. Currently this just reserves the remaining escapes. (e) {0} is now permitted. (The previous item is removed from the compiled pattern). 5. Changed all the names of code files so that the basic parts are no longer than 10 characters, and abolished the teeny "globals.c" file. 6. Changed the handling of character classes; they are now done with a 32-byte bit map always. 7. Added the -d and /D options to pcretest to make it possible to look at the internals of compilation without having to recompile pcre. Version 0.95 23-Sep-97 ---------------------- 1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or \x20 at the start of a run of normal characters. These were being treated as real characters, instead of the source characters being re-checked. Version 0.94 18-Sep-97 ---------------------- 1. The functions are now thread-safe, with the caveat that the global variables containing pointers to malloc() and free() or alternative functions are the same for all threads. 2. Get pcre_study() to generate a bitmap of initial characters for non- anchored patterns when this is possible, and use it if passed to pcre_exec(). Version 0.93 15-Sep-97 ---------------------- 1. /(b)|(:+)/ was computing an incorrect first character. 2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(), but not actually doing anything yet. 3. Treat "-" characters in classes that cannot be part of ranges as literals, as Perl does (e.g. [-az] or [az-]). 4. Set the anchored flag if a branch starts with .* or .*? because that tests all possible positions. 5. Split up into different modules to avoid including unneeded functions in a compiled binary. However, compile and exec are still in one module. The "study" function is split off. 6. The character tables are now in a separate module whose source is generated by an auxiliary program - but can then be edited by hand if required. There are now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or toupper() in the code. 7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and make them global. Abolish the function for setting them, as the caller can now set them directly. Version 0.92 11-Sep-97 ---------------------- 1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character (e.g. /a{1,3}/) was broken (I mis-optimized it). 2. Caseless matching was not working in character classes if the characters in the pattern were in upper case. 3. Make ranges like [W-c] work in the same way as Perl for caseless matching. 4. Make PCRE_ANCHORED public and accept as a compile option. 5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to pass them. 6. Give an error if bad option bits passed at compile or run time. 7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to pcretest to cause it to pass that flag. 8. Add pcre_info(), to get the number of identifying subpatterns, the stored options, and the first character, if set. 9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character. Version 0.91 10-Sep-97 ---------------------- 1. PCRE was failing to diagnose unlimited repeats of subpatterns that could match the empty string as in /(a*)*/. It was looping and ultimately crashing. 2. PCRE was looping on encountering an indefinitely repeated back reference to a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what Perl does - treats the match as successful. ****

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