=item *
-8-wide tabs (no exceptions!)
+4-wide indents for code, 2-wide indents for nested CPP C<#define>s,
+with 8-wide tabstops.
=item *
-4-wide indents for code, 2-wide indents for nested CPP #defines
+Use spaces for indentation, not tab characters.
+
+The codebase is a mixture of tabs and spaces for indentation, and we
+are moving to spaces only. Converting lines you're patching from 8-wide
+tabs to spaces will help this migration.
=item *
=over 4
-=item 1)
+=item *
These select Unicode rules. That means that in double-quotish strings,
the string is always converted to UTF-8 to force a Unicode
conversion isn't done, but if the character set modifier would
otherwise be C</d>, it is changed to C</u>.
-=item 2)
+=item *
If you use the form C<\N{I<character name>}>, the L<charnames> module
gets automatically loaded. This may not be suitable for the test level
to C<make> utilities to interact with their job schedulers.
Note that currently some test scripts may fail when run in parallel
-(most notably F<ext/IO/t/io_dir.t>). If necessary, run just the
+(most notably F<dist/IO/t/io_dir.t>). If necessary, run just the
failing scripts again sequentially and see if the failures go away.
=head2 Running tests by hand
Add a test that will take a fraction of a second normally, and minutes
otherwise, causing the test file to time out on failure.
+=head2 Building perl at older commits
+
+In the course of hacking on the Perl core distribution, you may have occasion
+to configure, build and test perl at an old commit. Sometimes C<make> will
+fail during this process. If that happens, you may be able to salvage the
+situation by using the Devel::PatchPerl library from CPAN (not included in the
+core) to bring the source code at that commit to a buildable state.
+
+Here's a real world example, taken from work done to resolve
+L<perl #72414|https://rt.perl.org/Ticket/Display.html?id=72414>.
+Use of F<Porting/bisect.pl> had identified commit
+C<ba77e4cc9d1ceebf472c9c5c18b2377ee47062e6> as the commit in which a bug was
+corrected. To confirm, a P5P developer wanted to configure and build perl at
+commit C<ba77e4c^> (presumably "bad") and then at C<ba77e4c> (presumably
+"good"). Normal configuration and build was attempted:
+
+ $ sh ./Configure -des -Dusedevel
+ $ make test_prep
+
+C<make>, however, failed with output (excerpted) like this:
+
+ cc -fstack-protector -L/usr/local/lib -o miniperl \
+ gv.o toke.o perly.o pad.o regcomp.o dump.o util.o \
+ mg.o reentr.o mro.o hv.o av.o run.o pp_hot.o sv.o \
+ pp.o scope.o pp_ctl.o pp_sys.o doop.o doio.o regexec.o \
+ utf8.o taint.o deb.o universal.o globals.o perlio.o \
+ perlapi.o numeric.o mathoms.o locale.o pp_pack.o pp_sort.o \
+ miniperlmain.o opmini.o perlmini.o
+ pp.o: In function `Perl_pp_pow':
+ pp.c:(.text+0x2db9): undefined reference to `pow'
+ ...
+ collect2: error: ld returned 1 exit status
+ makefile:348: recipe for target 'miniperl' failed
+ make: *** [miniperl] Error 1
+
+Another P5P contributor recommended installation and use of Devel::PatchPerl
+for this situation, first to determine the version of perl at the commit in
+question, then to patch the source code at that point to facilitate a build.
+
+ $ perl -MDevel::PatchPerl -e \
+ 'print Devel::PatchPerl->determine_version("/path/to/sourcecode"), "\n";'
+ 5.11.1
+ $ perl -MDevel::PatchPerl -e \
+ 'Devel::PatchPerl->patch_source("5.11.1", "/path/to/sourcecode");'
+
+Once the source was patched, C<./Configure> and C<make test_prep> were called
+and completed successfully, enabling confirmation of the findings in RT
+#72414.
+
=head1 MORE READING FOR GUTS HACKERS
To hack on the Perl guts, you'll need to read the following things:
=head1 CPAN TESTERS AND PERL SMOKERS
-The CPAN testers ( http://testers.cpan.org/ ) are a group of volunteers
+The CPAN testers ( L<http://testers.cpan.org/> ) are a group of volunteers
who test CPAN modules on a variety of platforms.
-Perl Smokers ( http://www.nntp.perl.org/group/perl.daily-build/ and
-http://www.nntp.perl.org/group/perl.daily-build.reports/ )
+Perl Smokers ( L<http://www.nntp.perl.org/group/perl.daily-build/> and
+L<http://www.nntp.perl.org/group/perl.daily-build.reports/> )
automatically test Perl source releases on platforms with various
configurations.
https://perl5.git.perl.org / perl5.git / blobdiff