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revision 507 by ph10, Wed Mar 10 16:08:01 2010 UTC revision 984 by ph10, Fri Jul 6 09:58:13 2012 UTC
# Line 25  Builducptable    A Perl script that crea Line 25  Builducptable    A Perl script that crea
25    
26  GenerateUtt.py   A Python script to generate part of the pcre_tables.c file  GenerateUtt.py   A Python script to generate part of the pcre_tables.c file
27                   that contains Unicode script names in a long string with                   that contains Unicode script names in a long string with
28                   offsets, which is tedious to maintain by hand.                   offsets, which is tedious to maintain by hand.
29    
30  ManyConfigTests  A shell script that runs "configure, make, test" a number of  ManyConfigTests  A shell script that runs "configure, make, test" a number of
31                   times with different configuration settings.                   times with different configuration settings.
32    
33  MultiStage2.py   A Python script that generates the file pcre_ucd.c from three  MultiStage2.py   A Python script that generates the file pcre_ucd.c from three
34                   Unicode data tables, which are themselves downloaded from the                   Unicode data tables, which are themselves downloaded from the
35                   Unicode web site. Run this script in the "maint" directory.                   Unicode web site. Run this script in the "maint" directory.
36                   The generated file contains the tables for a 2-stage lookup                   The generated file contains the tables for a 2-stage lookup
37                   of Unicode properties.                   of Unicode properties.
38    
39    pcre_chartables.c.non-standard
40                     This is a set of character tables that came from a Windows
41                     system. It has characters greater than 128 that are set as
42                     spaces, amongst other things. I kept it so that it can be
43                     used for testing from time to time.
44    
45  README           This file.  README           This file.
46    
47  Unicode.tables   The files in this directory, DerivedGeneralCategory.txt,  Unicode.tables   The files in this directory, DerivedGeneralCategory.txt,
48                   Scripts.txt and UnicodeData.txt, were downloaded from the                   Scripts.txt and UnicodeData.txt, were downloaded from the
49                   Unicode web site. They contain information about Unicode                   Unicode web site. They contain information about Unicode
50                   characters and scripts.                   characters and scripts.
# Line 71  can be run to generate a new version of Line 77  can be run to generate a new version of
77  run to generate the tricky tables for inclusion in pcre_tables.c.  run to generate the tricky tables for inclusion in pcre_tables.c.
78    
79  If MultiStage2.py gives the error "ValueError: list.index(x): x not in list",  If MultiStage2.py gives the error "ValueError: list.index(x): x not in list",
80  the cause is usually a missing (or misspelt) name in the list of scripts. I  the cause is usually a missing (or misspelt) name in the list of scripts. I
81  couldn't find a straightforward list of scripts on the Unicode site, but  couldn't find a straightforward list of scripts on the Unicode site, but
82  there's a useful Wikipedia page that list them, and notes the Unicode version  there's a useful Wikipedia page that list them, and notes the Unicode version
83  in which they were introduced:  in which they were introduced:
84    
85  http://en.wikipedia.org/wiki/Unicode_scripts#Table_of_Unicode_scripts  http://en.wikipedia.org/wiki/Unicode_scripts#Table_of_Unicode_scripts
# Line 83  pcre_ucd.c work properly, using the data Line 89  pcre_ucd.c work properly, using the data
89  of test characters. The source file ucptest.c must be updated whenever new  of test characters. The source file ucptest.c must be updated whenever new
90  Unicode script names are added.  Unicode script names are added.
91    
92  Note also that both the pcresyntax.3 and pcrepattern.3 man pages contain lists  Note also that both the pcresyntax.3 and pcrepattern.3 man pages contain lists
93  of Unicode script names.  of Unicode script names.
94    
95    
# Line 94  This section contains a checklist of thi Line 100  This section contains a checklist of thi
100  distribution for a new release.  distribution for a new release.
101    
102  . Ensure that the version number and version date are correct in configure.ac.  . Ensure that the version number and version date are correct in configure.ac.
103    
104    . Update the library version numbers in configure.ac according to the rules
105      given below.
106    
107  . If new build options have been added, ensure that they are added to the CMake  . If new build options have been added, ensure that they are added to the CMake
108    files as well as to the autoconf files.    files as well as to the autoconf files. The relevant files are CMakeLists.txt
109      and config-cmake.h.in. After making a release tarball, test it out with CMake
110      if there have been changes here.
111    
112  . Run ./autogen.sh to ensure everything is up-to-date.  . Run ./autogen.sh to ensure everything is up-to-date.
113    
114  . Compile and test with many different config options, and combinations of  . Compile and test with many different config options, and combinations of
115    options. The maint/ManyConfigTests script now encapsulates this testing.    options. Also, test with valgrind by running "RunTest valgrind" and
116      "RunGrepTest valgrind" (which takes quite a long time). The script
117      maint/ManyConfigTests now encapsulates this testing. It runs tests with
118      different configurations, and it also runs some of them with valgrind, all of
119      which can take quite some time.
120    
121  . Run perltest.pl on the test data for tests 1, 4, 6, and 11. The first two can  . Run perltest.pl on the test data for tests 1, 4, and 6. The output
   be run with Perl 5.8 or 5.10; the last two require Perl 5.10. The output  
122    should match the PCRE test output, apart from the version identification at    should match the PCRE test output, apart from the version identification at
123    the start of each test. The other tests are not Perl-compatible (they use    the start of each test. The other tests are not Perl-compatible (they use
124    various PCRE-specific features or options).    various PCRE-specific features or options).
125    
126  . Test with valgrind by running "RunTest valgrind". There is also "RunGrepTest  . It is possible to test with the emulated memmove() function by undefining
127    valgrind", though that takes quite a long time.    HAVE_MEMMOVE and HAVE_BCOPY in config.h, though I do not do this often. You
128      may see a number of "pcre_memmove defined but not used" warnings for the
129      modules in which there is no call to memmove(). These can be ignored.
130    
131    . Documentation: check AUTHORS, ChangeLog (check version and date), LICENCE,
132      NEWS (check version and date), NON-AUTOTOOLS-BUILD, and README. Many of these
133      won't need changing, but over the long term things do change.
134    
135    . I used to test new releases myself on a number of different operating
136      systems, using different compilers as well. For example, on Solaris it is
137      helpful to test using Sun's cc compiler as a change from gcc. Adding
138      -xarch=v9 to the cc options does a 64-bit test, but it also needs -S 64 for
139      pcretest to increase the stack size for test 2. Since I retired I can no
140      longer do this, but instead I rely on putting out release candidates for
141      folks on the pcre-dev list to test.
142    
143    
144    Updating version info for libtool
145    =================================
146    
147    This set of rules for updating library version information came from a web page
148    whose URL I have forgotten. The version information consists of three parts:
149    (current, revision, age).
150    
151  . It may also useful to test with Electric Fence, though the fact that it  1. Start with version information of 0:0:0 for each libtool library.
   grumbles for missing free() calls can be a nuisance. (A missing free() in  
   pcretest is hardly a big problem.) To build with EF, use:  
152    
153      LIBS='/usr/lib/libefence.a -lpthread' with ./configure.  2. Update the version information only immediately before a public release of
154       your software. More frequent updates are unnecessary, and only guarantee
155       that the current interface number gets larger faster.
156    
157    Then all normal runs use it to check for buffer overflow. Also run everything  3. If the library source code has changed at all since the last update, then
158    with:     increment revision; c:r:a becomes c:r+1:a.
159    
160      EF_PROTECT_BELOW=1 <whatever>  4. If any interfaces have been added, removed, or changed since the last
161       update, increment current, and set revision to 0.
162    
163    because there have been problems with lookbehinds that looked too far.  5. If any interfaces have been added since the last public release, then
164       increment age.
165    
166  . Test with the emulated memmove() function by undefining HAVE_MEMMOVE and  6. If any interfaces have been removed or changed since the last public
167    HAVE_BCOPY in config.h. You may see a number of "pcre_memmove defined but not     release, then set age to 0.
   used" warnings for the modules in which there is no call to memmove(). These  
   can be ignored.  
168    
169  . Documentation: check AUTHORS, COPYING, ChangeLog (check version and date),  The following explanation may help in understanding the above rules a bit
170    INSTALL, LICENCE, NEWS (check version and date), NON-UNIX-USE, and README.  better. Consider that there are three possible kinds of reaction from users to
171    Many of these won't need changing, but over the long term things do change.  changes in a shared library:
172    
173  . Man pages: Check all man pages for \ not followed by e or f or " because  1. Programs using the previous version may use the new version as a drop-in
174    that indicates a markup error. However, there is one exception: pcredemo.3,     replacement, and programs using the new version can also work with the
175    which is created from the pcredemo.c program. It contains three instances     previous one. In other words, no recompiling nor relinking is needed. In
176    of \\n.     this case, increment revision only, don't touch current or age.
177    
178  . When the release is built, test it on a number of different operating  2. Programs using the previous version may use the new version as a drop-in
179    systems if possible, and using different compilers as well. For example,     replacement, but programs using the new version may use APIs not present in
180    on Solaris it is helpful to test using Sun's cc compiler as a change from     the previous one. In other words, a program linking against the new version
181    gcc. Adding -xarch=v9 to the cc options does a 64-bit test, but it also     may fail if linked against the old version at run time. In this case, set
182    needs -S 64 for pcretest to increase the stack size for test 2.     revision to 0, increment current and age.
183    
184    3. Programs may need to be changed, recompiled, relinked in order to use the
185       new version. Increment current, set revision and age to 0.
186    
187    
188  Making a PCRE release  Making a PCRE release
189  =====================  =====================
190    
191  Run PrepareRelease and commit the files that it changes (by removing trailing  Run PrepareRelease and commit the files that it changes (by removing trailing
192  spaces). Then run "make distcheck" to create the tarballs and the zipball.  spaces). The first thing this script does is to run CheckMan on the man pages;
193  Double-check with "svn status", then create an SVN tagged copy:  if it finds any markup errors, it reports them and then aborts.
194    
195    Once PrepareRelease has run clean, run "make distcheck" to create the tarballs
196    and the zipball. Double-check with "svn status", then create an SVN tagged
197    copy:
198    
199    svn copy svn://vcs.exim.org/pcre/code/trunk \    svn copy svn://vcs.exim.org/pcre/code/trunk \
200             svn://vcs.exim.org/pcre/code/tags/pcre-8.xx             svn://vcs.exim.org/pcre/code/tags/pcre-8.xx
201    
202  Don't forget to update Freshmeat when the new release is out, and to tell  Don't forget to update Freshmeat when the new release is out, and to tell
203  webmaster@pcre.org and the mailing list. Also, update the list of version  webmaster@pcre.org and the mailing list. Also, update the list of version
204  numbers in Bugzilla (edit products).  numbers in Bugzilla (edit products).
205    
206    
# Line 184  others are relatively new. Line 227  others are relatively new.
227    
228    * "Ends with literal string" - note that a single character doesn't gain much    * "Ends with literal string" - note that a single character doesn't gain much
229      over the existing "required byte" (reqbyte) feature that just remembers one      over the existing "required byte" (reqbyte) feature that just remembers one
230      byte.      data unit.
231    
232    * These probably need to go in study():    * These probably need to go in pcre_study():
233    
234      o Remember an initial string rather than just 1 char?      o Remember an initial string rather than just 1 char?
235    
236      o A required byte from alternatives - not just the last char, but an      o A required data unit from alternatives - not just the last unit, but an
237        earlier one if common to all alternatives.        earlier one if common to all alternatives.
238    
239      o Friedl contains other ideas.      o Friedl contains other ideas.
240    
241      * pcre_study() does not set initial byte flags for Unicode property types
242        such as \p; I don't know how much benefit there would be for, for example,
243        setting the bits for 0-9 and all bytes >= xC0 when a pattern starts with
244        \p{N}.
245    
246      * There is scope for more "auto-possessifying" in connection with \p and \P.
247    
248  . If Perl gets to a consistent state over the settings of capturing sub-  . If Perl gets to a consistent state over the settings of capturing sub-
249    patterns inside repeats, see if we can match it. One example of the    patterns inside repeats, see if we can match it. One example of the
250    difference is the matching of /(main(O)?)+/ against mainOmain, where PCRE    difference is the matching of /(main(O)?)+/ against mainOmain, where PCRE
# Line 203  others are relatively new. Line 253  others are relatively new.
253    
254  . Perl 6 will be a revolution. Is it a revolution too far for PCRE?  . Perl 6 will be a revolution. Is it a revolution too far for PCRE?
255    
 . Unicode  
   
   * Note that in Perl, \s matches \pZ and similarly for \d, \w and the POSIX  
     character classes. For the moment, I've chosen not to support this for  
     backward compatibility, for speed, and because it would be messy to  
     implement.  
   
   * A different approach to Unicode might be to use a typedef to do everything  
     in unsigned shorts instead of unsigned chars. Actually, we'd have to have a  
     new typedef to distinguish data from bits of compiled pattern that are in  
     bytes, I think. There would need to be conversion functions in and out. I  
     don't think this is particularly trivial - and anyway, Unicode now has  
     characters that need more than 16 bits, so is this at all sensible?  
   
   * There has been a request for direct support of 16-bit characters and  
     UTF-16. However, since Unicode is moving beyond purely 16-bit characters,  
     is this worth it at all? One possible way of handling 16-bit characters  
     would be to "load" them in the same way that UTF-8 characters are loaded.  
   
256  . Allow errorptr and erroroffset to be NULL. I don't like this idea.  . Allow errorptr and erroroffset to be NULL. I don't like this idea.
257    
258  . Line endings:  . Line endings:
# Line 247  others are relatively new. Line 278  others are relatively new.
278    support --outputfile=name.    support --outputfile=name.
279    
280  . Consider making UTF-8 and UCP the default for PCRE n.0 for some n > 8.  . Consider making UTF-8 and UCP the default for PCRE n.0 for some n > 8.
281      (And now presumably UTF-16 and UCP for the 16-bit library.)
282    
283  . Add a user pointer to pcre_malloc/free functions -- some option would be  . Add a user pointer to pcre_malloc/free functions -- some option would be
284    needed to retain backward compatibility.    needed to retain backward compatibility.
# Line 261  others are relatively new. Line 293  others are relatively new.
293  . Wild thought: the ability to compile from PCRE's internal byte code to a real  . Wild thought: the ability to compile from PCRE's internal byte code to a real
294    FSM and a very fast (third) matcher to process the result. There would be    FSM and a very fast (third) matcher to process the result. There would be
295    even more restrictions than for pcre_dfa_exec(), however. This is not easy.    even more restrictions than for pcre_dfa_exec(), however. This is not easy.
296      This is probably obsolete now that we have the JIT support.
297    
298  . Should pcretest have some private locale data, to avoid relying on the  . Should pcretest have some private locale data, to avoid relying on the
299    available locales for the test data, since different OS have different ideas?    available locales for the test data, since different OS have different ideas?
# Line 271  others are relatively new. Line 304  others are relatively new.
304    
305  . Someone suggested --disable-callout to save code space when callouts are  . Someone suggested --disable-callout to save code space when callouts are
306    never wanted. This seems rather marginal.    never wanted. This seems rather marginal.
307    
308  . Check names that consist entirely of digits: PCRE allows, but do Perl and  . Check names that consist entirely of digits: PCRE allows, but do Perl and
309    Python, etc?    Python, etc?
310    
311  . A user suggested a parameter to limit the length of string matched, for  . A user suggested a parameter to limit the length of string matched, for
312    example if the parameter is N, the current match should fail if the matched    example if the parameter is N, the current match should fail if the matched
313    substring exceeds N. This could apply to both match functions. The value    substring exceeds N. This could apply to both match functions. The value
314    could be a new field in the extra block.    could be a new field in the extra block.
315    
316  . Callouts with arguments: (?Cn:ARG) for instance.  . Callouts with arguments: (?Cn:ARG) for instance.
317    
318  . A user is going to supply a patch to generalize the API for user-specific  . A user is going to supply a patch to generalize the API for user-specific
319    memory allocation so that it is more flexible in threaded environments. This    memory allocation so that it is more flexible in threaded environments. This
320    was promised a long time ago, and never appeared...    was promised a long time ago, and never appeared. However, this is a live
321      issue not only for threaded environments, but for libraries that use PCRE and
322      want not to be beholden to their caller's memory allocation.
323    
324    . Write a wrapper to maintain a structure with specified runtime parameters,
325      such as recurse limit, and pass these to PCRE each time it is called. Also
326      maybe malloc and free. A user sent a prototype. This relates the the previous
327      item.
328    
329  . Write a function that generates random matching strings for a compiled regex.  . Write a function that generates random matching strings for a compiled regex.
330    
331  . Write a wrapper to maintain a structure with specified runtime parameters,  . Pcregrep: an option to specify the output line separator, either as a string
332    such as recurse limit, and pass these to PCRE each time it is called. Also    or select from a fixed list. This is not dead easy, because at the moment it
   maybe malloc and free. A user sent a prototype.  
   
 . Pcregrep: an option to specify the output line separator, either as a string  
   or select from a fixed list. This is not dead easy, because at the moment it  
333    outputs whatever is in the input file.    outputs whatever is in the input file.
334    
335  . Improve the code for duplicate checking in pcre_dfa_exec(). An incomplete,  . Improve the code for duplicate checking in pcre_dfa_exec(). An incomplete,
336    non-thread-safe patch showed that this can help performance for patterns    non-thread-safe patch showed that this can help performance for patterns
337    where there are many alternatives. However, a simple thread-safe    where there are many alternatives. However, a simple thread-safe
338    implementation that I tried made things worse in many simple cases, so this    implementation that I tried made things worse in many simple cases, so this
339    is not an obviously good thing.    is not an obviously good thing.
340    
341  . Make the longest lookbehind available via pcre_fullinfo(). This is not  . Make the longest lookbehind available via pcre_fullinfo(). This is not
342    straightforward because lookbehinds can be nested inside lookbehinds. This    straightforward because lookbehinds can be nested inside lookbehinds. This
343    case will have to be identified, and the amounts added. This should then give    case will have to be identified, and the amounts added. This should then give
344    the maximum possible lookbehind length. The reason for wanting this is to    the maximum possible lookbehind length. The reason for wanting this is to
345    help when implementing multi-segment matching using pcre_exec() with partial    help when implementing multi-segment matching using pcre_exec() with partial
346    matching and overlapping segments.    matching and overlapping segments.
347    
348  . PCRE cannot at present distinguish between subpatterns with different names,  . PCRE cannot at present distinguish between subpatterns with different names,
349    but the same number (created by the use of ?|). In order to do so, a way of    but the same number (created by the use of ?|). In order to do so, a way of
350    remembering *which* subpattern numbered n matched is needed. Bugzilla #760.    remembering *which* subpattern numbered n matched is needed. Bugzilla #760.
351      Now that (*MARK) has been implemented, it can perhaps be used as a way round
352  . Instead of having #ifdef HAVE_CONFIG_H in each module, put #include    this problem.
353    
354    . Instead of having #ifdef HAVE_CONFIG_H in each module, put #include
355    "something" and the the #ifdef appears only in one place, in "something".    "something" and the the #ifdef appears only in one place, in "something".
   
 . Support for (*MARK) and arguments for (*PRUNE) and friends.  
356    
357  Philip Hazel  Philip Hazel
358  Email local part: ph10  Email local part: ph10
359  Email domain: cam.ac.uk  Email domain: cam.ac.uk
360  Last updated: 10 March 2010  Last updated: 18 June 2012

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