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revision 686 by ph10, Tue Sep 6 16:06:36 2011 UTC revision 707 by ph10, Fri Sep 23 10:32:53 2011 UTC
# Line 41  PCRE - Perl-compatible regular expressio Line 41  PCRE - Perl-compatible regular expressio
41  .PP  .PP
42  .B void pcre_jit_stack_free(pcre_jit_stack *\fIstack\fP);  .B void pcre_jit_stack_free(pcre_jit_stack *\fIstack\fP);
43  .PP  .PP
44  .B void pcre_assign_jit_stack(pcre_extra *\fIextra\fP,  .B void pcre_assign_jit_stack(pcre_extra *\fIextra\fP,
45  .ti +5n  .ti +5n
46  .B pcre_jit_callback \fIcallback\fP, void *\fIdata\fP);  .B pcre_jit_callback \fIcallback\fP, void *\fIdata\fP);
47  .PP  .PP
# Line 315  callout function pointed to by \fBpcre_c Line 315  callout function pointed to by \fBpcre_c
315  The compiled form of a regular expression is not altered during matching, so  The compiled form of a regular expression is not altered during matching, so
316  the same compiled pattern can safely be used by several threads at once.  the same compiled pattern can safely be used by several threads at once.
317  .P  .P
318  If the just-in-time optimization feature is being used, it needs separate  If the just-in-time optimization feature is being used, it needs separate
319  memory stack areas for each thread. See the  memory stack areas for each thread. See the
320  .\" HREF  .\" HREF
321  \fBpcrejit\fP  \fBpcrejit\fP
# Line 365  properties is available; otherwise it is Line 365  properties is available; otherwise it is
365  .sp  .sp
366    PCRE_CONFIG_JIT    PCRE_CONFIG_JIT
367  .sp  .sp
368  The output is an integer that is set to one if support for just-in-time  The output is an integer that is set to one if support for just-in-time
369  compiling is available; otherwise it is set to zero.  compiling is available; otherwise it is set to zero.
370  .sp  .sp
371    PCRE_CONFIG_NEWLINE    PCRE_CONFIG_NEWLINE
372  .sp  .sp
# Line 888  If studying the pattern does not produce Line 888  If studying the pattern does not produce
888  wants to pass any of the other fields to \fBpcre_exec()\fP or  wants to pass any of the other fields to \fBpcre_exec()\fP or
889  \fBpcre_dfa_exec()\fP, it must set up its own \fBpcre_extra\fP block.  \fBpcre_dfa_exec()\fP, it must set up its own \fBpcre_extra\fP block.
890  .P  .P
891  The second argument of \fBpcre_study()\fP contains option bits. There is only  The second argument of \fBpcre_study()\fP contains option bits. There is only
892  one option: PCRE_STUDY_JIT_COMPILE. If this is set, and the just-in-time  one option: PCRE_STUDY_JIT_COMPILE. If this is set, and the just-in-time
893  compiler is available, the pattern is further compiled into machine code that  compiler is available, the pattern is further compiled into machine code that
894  executes much faster than the \fBpcre_exec()\fP matching function. If  executes much faster than the \fBpcre_exec()\fP matching function. If
895  the just-in-time compiler is not available, this option is ignored. All other  the just-in-time compiler is not available, this option is ignored. All other
896  bits in the \fIoptions\fP argument must be zero.  bits in the \fIoptions\fP argument must be zero.
897  .P  .P
898  JIT compilation is a heavyweight optimization. It can take some time for  JIT compilation is a heavyweight optimization. It can take some time for
899  patterns to be analyzed, and for one-off matches and simple patterns the  patterns to be analyzed, and for one-off matches and simple patterns the
900  benefit of faster execution might be offset by a much slower study time.  benefit of faster execution might be offset by a much slower study time.
901  Not all patterns can be optimized by the JIT compiler. For those that cannot be  Not all patterns can be optimized by the JIT compiler. For those that cannot be
902  handled, matching automatically falls back to the \fBpcre_exec()\fP  handled, matching automatically falls back to the \fBpcre_exec()\fP
903  interpreter. For more details, see the  interpreter. For more details, see the
904  .\" HREF  .\" HREF
# Line 920  API for release 8.20. For earlier versio Line 920  API for release 8.20. For earlier versio
920  where PCRE_STUDY_JIT_COMPILE is not used, but it is advisable to change to the  where PCRE_STUDY_JIT_COMPILE is not used, but it is advisable to change to the
921  new function when convenient.  new function when convenient.
922  .P  .P
923  This is a typical way in which \fBpcre_study\fP() is used (except that in a  This is a typical way in which \fBpcre_study\fP() is used (except that in a
924  real application there should be tests for errors):  real application there should be tests for errors):
925  .sp  .sp
926    int rc;    int rc;
# Line 932  real application there should be tests f Line 932  real application there should be tests f
932      0,              /* no options */      0,              /* no options */
933      &error);        /* set to NULL or points to a message */      &error);        /* set to NULL or points to a message */
934    rc = pcre_exec(   /* see below for details of pcre_exec() options */    rc = pcre_exec(   /* see below for details of pcre_exec() options */
935      re, sd, "subject", 7, 0, 0, ovector, 30);      re, sd, "subject", 7, 0, 0, ovector, 30);
936    ...    ...
937    pcre_free_study(sd);    pcre_free_study(sd);
938    pcre_free(re);    pcre_free(re);
939  .sp  .sp
940  Studying a pattern does two things: first, a lower bound for the length of  Studying a pattern does two things: first, a lower bound for the length of
941  subject string that is needed to match the pattern is computed. This does not  subject string that is needed to match the pattern is computed. This does not
# Line 950  single fixed starting character. A bitma Line 950  single fixed starting character. A bitma
950  created. This speeds up finding a position in the subject at which to start  created. This speeds up finding a position in the subject at which to start
951  matching.  matching.
952  .P  .P
953  These two optimizations apply to both \fBpcre_exec()\fP and  These two optimizations apply to both \fBpcre_exec()\fP and
954  \fBpcre_dfa_exec()\fP. However, they are not used by \fBpcre_exec()\fP if  \fBpcre_dfa_exec()\fP. However, they are not used by \fBpcre_exec()\fP if
955  \fBpcre_study()\fP is called with the PCRE_STUDY_JIT_COMPILE option, and  \fBpcre_study()\fP is called with the PCRE_STUDY_JIT_COMPILE option, and
956  just-in-time compiling is successful. The optimizations can be disabled by  just-in-time compiling is successful. The optimizations can be disabled by
957  setting the PCRE_NO_START_OPTIMIZE option when calling \fBpcre_exec()\fP or  setting the PCRE_NO_START_OPTIMIZE option when calling \fBpcre_exec()\fP or
# Line 1122  Return 1 if the (?J) or (?-J) option set Line 1122  Return 1 if the (?J) or (?-J) option set
1122  .sp  .sp
1123    PCRE_INFO_JIT    PCRE_INFO_JIT
1124  .sp  .sp
1125  Return 1 if the pattern was studied with the PCRE_STUDY_JIT_COMPILE option, and  Return 1 if the pattern was studied with the PCRE_STUDY_JIT_COMPILE option, and
1126  just-in-time compiling was successful. The fourth argument should point to an  just-in-time compiling was successful. The fourth argument should point to an
1127  \fBint\fP variable. A return value of 0 means that JIT support is not available  \fBint\fP variable. A return value of 0 means that JIT support is not available
1128  in this version of PCRE, or that the pattern was not studied with the  in this version of PCRE, or that the pattern was not studied with the
1129  PCRE_STUDY_JIT_COMPILE option, or that the JIT compiler could not handle this  PCRE_STUDY_JIT_COMPILE option, or that the JIT compiler could not handle this
1130  particular pattern. See the  particular pattern. See the
1131  .\" HREF  .\" HREF
1132  \fBpcrejit\fP  \fBpcrejit\fP
# Line 1331  is different. (This seems a highly unlik Line 1331  is different. (This seems a highly unlik
1331  The function \fBpcre_exec()\fP is called to match a subject string against a  The function \fBpcre_exec()\fP is called to match a subject string against a
1332  compiled pattern, which is passed in the \fIcode\fP argument. If the  compiled pattern, which is passed in the \fIcode\fP argument. If the
1333  pattern was studied, the result of the study should be passed in the  pattern was studied, the result of the study should be passed in the
1334  \fIextra\fP argument. This function is the main matching facility of the  \fIextra\fP argument. You can call \fBpcre_exec()\fP with the same \fIcode\fP
1335  library, and it operates in a Perl-like manner. For specialist use there is  and \fIextra\fP arguments as many times as you like, in order to match
1336  also an alternative matching function, which is described  different subject strings with the same pattern.
1337    .P
1338    This function is the main matching facility of the library, and it operates in
1339    a Perl-like manner. For specialist use there is also an alternative matching
1340    function, which is described
1341  .\" HTML <a href="#dfamatch">  .\" HTML <a href="#dfamatch">
1342  .\" </a>  .\" </a>
1343  below  below
# Line 1377  fields (not necessarily in this order): Line 1381  fields (not necessarily in this order):
1381  .sp  .sp
1382    unsigned long int \fIflags\fP;    unsigned long int \fIflags\fP;
1383    void *\fIstudy_data\fP;    void *\fIstudy_data\fP;
1384    void *\fIexecutable_jit\fP;    void *\fIexecutable_jit\fP;
1385    unsigned long int \fImatch_limit\fP;    unsigned long int \fImatch_limit\fP;
1386    unsigned long int \fImatch_limit_recursion\fP;    unsigned long int \fImatch_limit_recursion\fP;
1387    void *\fIcallout_data\fP;    void *\fIcallout_data\fP;
# Line 1388  The \fIflags\fP field is a bitmap that s Line 1392  The \fIflags\fP field is a bitmap that s
1392  are set. The flag bits are:  are set. The flag bits are:
1393  .sp  .sp
1394    PCRE_EXTRA_STUDY_DATA    PCRE_EXTRA_STUDY_DATA
1395    PCRE_EXTRA_EXECUTABLE_JIT    PCRE_EXTRA_EXECUTABLE_JIT
1396    PCRE_EXTRA_MATCH_LIMIT    PCRE_EXTRA_MATCH_LIMIT
1397    PCRE_EXTRA_MATCH_LIMIT_RECURSION    PCRE_EXTRA_MATCH_LIMIT_RECURSION
1398    PCRE_EXTRA_CALLOUT_DATA    PCRE_EXTRA_CALLOUT_DATA
# Line 1411  calls repeatedly (sometimes recursively) Line 1415  calls repeatedly (sometimes recursively)
1415  imposed on the number of times this function is called during a match, which  imposed on the number of times this function is called during a match, which
1416  has the effect of limiting the amount of backtracking that can take place. For  has the effect of limiting the amount of backtracking that can take place. For
1417  patterns that are not anchored, the count restarts from zero for each position  patterns that are not anchored, the count restarts from zero for each position
1418  in the subject string.  in the subject string.
1419  .P  .P
1420  When \fBpcre_exec()\fP is called with a pattern that was successfully studied  When \fBpcre_exec()\fP is called with a pattern that was successfully studied
1421  with the PCRE_STUDY_JIT_COMPILE option, the way that the matching is executed  with the PCRE_STUDY_JIT_COMPILE option, the way that the matching is executed
1422  is entirely different. However, there is still the possibility of runaway  is entirely different. However, there is still the possibility of runaway
1423  matching that goes on for a very long time, and so the \fImatch_limit\fP value  matching that goes on for a very long time, and so the \fImatch_limit\fP value
1424  is also used in this case (but in a different way) to limit how long the  is also used in this case (but in a different way) to limit how long the
1425  matching can continue.  matching can continue.
# Line 1431  The \fImatch_limit_recursion\fP field is Line 1435  The \fImatch_limit_recursion\fP field is
1435  instead of limiting the total number of times that \fBmatch()\fP is called, it  instead of limiting the total number of times that \fBmatch()\fP is called, it
1436  limits the depth of recursion. The recursion depth is a smaller number than the  limits the depth of recursion. The recursion depth is a smaller number than the
1437  total number of calls, because not all calls to \fBmatch()\fP are recursive.  total number of calls, because not all calls to \fBmatch()\fP are recursive.
1438  This limit is of use only if it is set smaller than \fImatch_limit\fP.  This limit is of use only if it is set smaller than \fImatch_limit\fP.
1439  .P  .P
1440  Limiting the recursion depth limits the amount of machine stack that can be  Limiting the recursion depth limits the amount of machine stack that can be
1441  used, or, when PCRE has been compiled to use memory on the heap instead of the  used, or, when PCRE has been compiled to use memory on the heap instead of the
# Line 1500  PCRE_PARTIAL_HARD. Line 1504  PCRE_PARTIAL_HARD.
1504  If the pattern was successfully studied with the PCRE_STUDY_JIT_COMPILE option,  If the pattern was successfully studied with the PCRE_STUDY_JIT_COMPILE option,
1505  the only supported options for JIT execution are PCRE_NO_UTF8_CHECK,  the only supported options for JIT execution are PCRE_NO_UTF8_CHECK,
1506  PCRE_NOTBOL, PCRE_NOTEOL, PCRE_NOTEMPTY, and PCRE_NOTEMPTY_ATSTART. Note in  PCRE_NOTBOL, PCRE_NOTEOL, PCRE_NOTEMPTY, and PCRE_NOTEMPTY_ATSTART. Note in
1507  particular that partial matching is not supported. If an unsupported option is  particular that partial matching is not supported. If an unsupported option is
1508  used, JIT execution is disabled and the normal interpretive code in  used, JIT execution is disabled and the normal interpretive code in
1509  \fBpcre_exec()\fP is run.  \fBpcre_exec()\fP is run.
1510  .sp  .sp
1511    PCRE_ANCHORED    PCRE_ANCHORED
# Line 1825  consider the pattern Line 1829  consider the pattern
1829  If a vector of 6 elements (allowing for only 1 captured substring) is given  If a vector of 6 elements (allowing for only 1 captured substring) is given
1830  with subject string "abd", \fBpcre_exec()\fP will try to set the second  with subject string "abd", \fBpcre_exec()\fP will try to set the second
1831  captured string, thereby recording a vector overflow, before failing to match  captured string, thereby recording a vector overflow, before failing to match
1832  "c" and backing up to try the second alternative. The zero return, however,  "c" and backing up to try the second alternative. The zero return, however,
1833  does correctly indicate that the maximum number of slots (namely 2) have been  does correctly indicate that the maximum number of slots (namely 2) have been
1834  filled. In similar cases where there is temporary overflow, but the final  filled. In similar cases where there is temporary overflow, but the final
1835  number of used slots is actually less than the maximum, a non-zero value is  number of used slots is actually less than the maximum, a non-zero value is
# Line 2009  time. Line 2013  time.
2013  .sp  .sp
2014    PCRE_ERROR_JIT_STACKLIMIT (-27)    PCRE_ERROR_JIT_STACKLIMIT (-27)
2015  .sp  .sp
2016  This error is returned when a pattern that was successfully studied using the  This error is returned when a pattern that was successfully studied using the
2017  PCRE_STUDY_JIT_COMPILE option is being matched, but the memory available for  PCRE_STUDY_JIT_COMPILE option is being matched, but the memory available for
2018  the just-in-time processing stack is not large enough. See the  the just-in-time processing stack is not large enough. See the
2019  .\" HREF  .\" HREF
2020  \fBpcrejit\fP  \fBpcrejit\fP
2021  .\"  .\"
2022  documentation for more details.  documentation for more details.
2023  .P  .P
2024  Error numbers -16 to -20 and -22 are not used by \fBpcre_exec()\fP.  Error numbers -16 to -20 and -22 are not used by \fBpcre_exec()\fP.
2025  .  .
# Line 2456  returns data, even though the meaning of Line 2460  returns data, even though the meaning of
2460  The strings are returned in reverse order of length; that is, the longest  The strings are returned in reverse order of length; that is, the longest
2461  matching string is given first. If there were too many matches to fit into  matching string is given first. If there were too many matches to fit into
2462  \fIovector\fP, the yield of the function is zero, and the vector is filled with  \fIovector\fP, the yield of the function is zero, and the vector is filled with
2463  the longest matches. Unlike \fBpcre_exec()\fP, \fBpcre_dfa_exec()\fP can use  the longest matches. Unlike \fBpcre_exec()\fP, \fBpcre_dfa_exec()\fP can use
2464  the entire \fIovector\fP for returning matched strings.  the entire \fIovector\fP for returning matched strings.
2465  .  .
2466  .  .
# Line 2526  Cambridge CB2 3QH, England. Line 2530  Cambridge CB2 3QH, England.
2530  .rs  .rs
2531  .sp  .sp
2532  .nf  .nf
2533  Last updated: 06 September 2011  Last updated: 23 September 2011
2534  Copyright (c) 1997-2011 University of Cambridge.  Copyright (c) 1997-2011 University of Cambridge.
2535  .fi  .fi

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