=item Is the implementation generic enough to be portable?
The worst patches make use of a system-specific features. It's highly
-unlikely that nonportable additions to the Perl language will be
+unlikely that non-portable additions to the Perl language will be
accepted.
=item Is the implementation tested?
by Robert Spier. Become an administrator, and close any bugs you can get
your sticky mitts on:
- http://rt.perl.org/rt3/
+ http://bugs.perl.org/
To email the bug system administrators:
resembles the code found in L<perlembed>; most of the real action takes
place in F<perl.c>
+F<perlmain.c> is generated by L<writemain> from F<miniperlmain.c> at
+make time, so you should make perl to follow this along.
+
First, F<perlmain.c> allocates some memory and constructs a Perl
-interpreter:
+interpreter, along these lines:
1 PERL_SYS_INIT3(&argc,&argv,&env);
2
own C<malloc> as defined in F<malloc.c> if you selected that option at
configure time.
-Next, in line 7, we construct the interpreter; this sets up all the
-special variables that Perl needs, the stacks, and so on.
+Next, in line 7, we construct the interpreter using perl_construct,
+also in F<perl.c>; this sets up all the special variables that Perl
+needs, the stacks, and so on.
Now we pass Perl the command line options, and tell it to go:
exitstatus = perl_parse(my_perl, xs_init, argc, argv, (char **)NULL);
- if (!exitstatus) {
- exitstatus = perl_run(my_perl);
- }
+ if (!exitstatus)
+ perl_run(my_perl);
+ exitstatus = perl_destruct(my_perl);
+
+ perl_free(my_perl);
C<perl_parse> is actually a wrapper around C<S_parse_body>, as defined
in F<perl.c>, which processes the command line options, sets up any
=item Exception handing
-Perl's exception handing (i.e. C<die> etc) is built on top of the low-level
+Perl's exception handing (i.e. C<die> etc.) is built on top of the low-level
C<setjmp()>/C<longjmp()> C-library functions. These basically provide a
way to capture the current PC and SP registers and later restore them; i.e.
a C<longjmp()> continues at the point in code where a previous C<setjmp()>
=back
The following flags would be nice to have but they would first need
-their own Stygian stablemaster:
+their own Augean stablemaster:
=over 4
You may find it helpful to have a "macro dictionary", which you can
produce by saying C<cpp -dM perl.c | sort>. Even then, F<cpp> won't
-recursively apply those macros for you.
+recursively apply those macros for you.
=head2 gdb macro support
F<dump.c>; these work a little like an internal
L<Devel::Peek|Devel::Peek>, but they also cover OPs and other structures
that you can't get at from Perl. Let's take an example. We'll use the
-C<$a = $b + $c> we used before, but give it a bit of context:
+C<$a = $b + $c> we used before, but give it a bit of context:
C<$b = "6XXXX"; $c = 2.3;>. Where's a good place to stop and poke around?
What about C<pp_add>, the function we examined earlier to implement the
directly (if C<SvNOK> is set) or by calling the C<sv_2nv> function.
C<TOPs> takes the next SV from the top of the stack - yes, C<POPn> uses
C<TOPs> - but doesn't remove it. We then use C<SvNV> to get the NV from
-C<leftsv> in the same way as before - yes, C<POPn> uses C<SvNV>.
+C<leftsv> in the same way as before - yes, C<POPn> uses C<SvNV>.
Since we don't have an NV for C<$b>, we'll have to use C<sv_2nv> to
convert it. If we step again, we'll find ourselves there:
All right, we've now had a look at how to navigate the Perl sources and
some things you'll need to know when fiddling with them. Let's now get
on and create a simple patch. Here's something Larry suggested: if a
-C<U> is the first active format during a C<pack>, (for example,
+C<U> is the first active format during a C<pack>, (for example,
C<pack "U3C8", @stuff>) then the resulting string should be treated as
UTF-8 encoded.
The regression tests for each operator live in F<t/op/>, and so we
make a copy of F<t/op/pack.t> to F<t/op/pack.t~>. Now we can add our
tests to the end. First, we'll test that the C<U> does indeed create
-Unicode strings.
+Unicode strings.
t/op/pack.t has a sensible ok() function, but if it didn't we could
use the one from t/test.pl.
we can write the more sensible (see L<Test::More> for a full
explanation of is() and other testing functions).
- is( "1.20.300.4000", sprintf "%vd", pack("U*",1,20,300,4000),
- "U* produces unicode" );
+ is( "1.20.300.4000", sprintf "%vd", pack("U*",1,20,300,4000),
+ "U* produces Unicode" );
Now we'll test that we got that space-at-the-beginning business right:
the first active format:
isnt( v1.20.300.4000, sprintf "%vd", pack("C0U*",1,20,300,4000),
- "U* not first isn't unicode" );
+ "U* not first isn't Unicode" );
Mustn't forget to change the number of tests which appears at the top,
or else the automated tester will get confused. This will either look
here. There are still some bits and pieces hanging around in here
that need to be moved. Perhaps you could move them? Thanks!
+=item F<t/mro/>
+
+Tests for perl's method resolution order implementations
+(see L<mro>).
+
=item F<t/op/>
Tests for perl's built in functions that don't fit into any of the
working on. This is a measure to prevent a high-level failure (such
as Config.pm breaking) from causing basic functionality tests to fail.
-=over 4
+=over 4
=item t/base t/comp
=back
When you say "make test" Perl uses the F<t/TEST> program to run the
-test suite (except under Win32 where it uses F<t/harness> instead.)
-All tests are run from the F<t/> directory, B<not> the directory
-which contains the test. This causes some problems with the tests
+test suite (except under Win32 where it uses F<t/harness> instead.)
+All tests are run from the F<t/> directory, B<not> the directory
+which contains the test. This causes some problems with the tests
in F<lib/>, so here's some opportunity for some patching.
You must be triply conscious of cross-platform concerns. This usually
=item minitest
Run F<miniperl> on F<t/base>, F<t/comp>, F<t/cmd>, F<t/run>, F<t/io>,
-F<t/op>, and F<t/uni> tests.
+F<t/op>, F<t/uni> and F<t/mro> tests.
=item test.valgrind check.valgrind utest.valgrind ucheck.valgrind
harness -v -torture -re LIST OF PATTERNS TO MATCH
If C<LIST OF FILES TO TEST> is omitted the file list is obtained from
-the manifest. The file list may include shell wildcards which will be
+the manifest. The file list may include shell wildcards which will be
expanded out.
=over 4
=item -v
-Run the tests under verbose mode so you can see what tests were run,
+Run the tests under verbose mode so you can see what tests were run,
and debug outbut.
=item -torture
=item -re LIST OF PATTERNS
-Filter the file list so that all the test files run match
+Filter the file list so that all the test files run match
/(LIST|OF|PATTERNS)/. Note that with this form the patterns
are joined by '|' and you cannot supply a list of files, instead
the test files are obtained from the MANIFEST.
except that the harnesses set up some environment variables that may
affect the execution of the test :
-=over 4
+=over 4
=item PERL_CORE=1
=back
+=head3 Other environment variables that may influence tests
+
+=over 4
+
+=item PERL_TEST_Net_Ping
+
+Setting this variable runs all the Net::Ping modules tests,
+otherwise some tests that interact with the outside world are skipped.
+See L<perl58delta>.
+
+=item PERL_TEST_NOVREXX
+
+Setting this variable skips the vrexx.t tests for OS2::REXX.
+
+=item PERL_TEST_NUMCONVERTS
+
+This sets a variable in op/numconvert.t.
+
+=back
+
+See also the documentation for the Test and Test::Harness modules,
+for more environment variables that affect testing.
+
=head2 Common problems when patching Perl source code
Perl source plays by ANSI C89 rules: no C99 (or C++) extensions. In
#endif
How does the HAS_QUUX become defined where it needs to be? Well, if
-Foonix happens to be UNIXy enought to be able to run the Configure
+Foonix happens to be UNIXy enough to be able to run the Configure
script, and Configure has been taught about detecting and testing
quux(), the HAS_QUUX will be correctly defined. In other platforms,
the corresponding configuration step will hopefully do the same.
=item *
-malloc(0), realloc(0), calloc(0, 0) are nonportable. To be portable
+malloc(0), realloc(0), calloc(0, 0) are non-portable. To be portable
allocate at least one byte. (In general you should rarely need to
work at this low level, but instead use the various malloc wrappers.)
Once you've compiled a perl suitable for Purify'ing, then you
can just:
- make pureperl
+ make pureperl
which creates a binary named 'pureperl' that has been Purify'ed.
This binary is used in place of the standard 'perl' binary
make pureperl
cd t
- ../pureperl -I../lib harness
+ ../pureperl -I../lib harness
which would run Perl on test.pl and report any memory problems.
You should add -DPURIFY to the DEFINES line so the DEFINES
line looks something like:
- DEFINES = -DWIN32 -D_CONSOLE -DNO_STRICT $(CRYPT_FLAG) -DPURIFY=1
+ DEFINES = -DWIN32 -D_CONSOLE -DNO_STRICT $(CRYPT_FLAG) -DPURIFY=1
to disable Perl's arena memory allocation functions, as
well as to force use of memory allocation functions derived
cd win32
make
cd ../t
- purify ../perl -I../lib harness
+ purify ../perl -I../lib harness
which would instrument Perl in memory, run Perl on test.pl,
then finally report any memory problems.
=head2 valgrind
The excellent valgrind tool can be used to find out both memory leaks
-and illegal memory accesses. As of August 2003 it unfortunately works
-only on x86 (ELF) Linux. The special "test.valgrind" target can be used
-to run the tests under valgrind. Found errors and memory leaks are
-logged in files named F<test.valgrind>.
+and illegal memory accesses. As of version 3.3.0, Valgrind only
+supports Linux on x86, x86-64 and PowerPC. The special "test.valgrind"
+target can be used to run the tests under valgrind. Found errors
+and memory leaks are logged in files named F<testfile.valgrind>.
+
+Valgrind also provides a cachegrind tool, invoked on perl as:
+
+ VG_OPTS=--tool=cachegrind make test.valgrind
As system libraries (most notably glibc) are also triggering errors,
valgrind allows to suppress such errors using suppression files. The
For more detailed explanation of the available commands and output
formats, see your own local documentation of gprof.
+quick hint:
+
+ $ sh Configure -des -Dusedevel -Doptimize='-g' -Accflags='-pg' -Aldflags='-pg' && make
+ $ ./perl someprog # creates gmon.out in current directory
+ $ gprof perl > out
+ $ view out
+
=head2 GCC gcov Profiling
Starting from GCC 3.0 I<basic block profiling> is officially available
http://gcc.gnu.org/onlinedocs/gcc-3.0/gcc_8.html#SEC132
+quick hint:
+
+ $ sh Configure -des -Doptimize='-g' -Accflags='-fprofile-arcs -ftest-coverage' \
+ -Aldflags='-fprofile-arcs -ftest-coverage' && make perl.gcov
+ $ rm -f regexec.c.gcov regexec.gcda
+ $ ./perl.gcov
+ $ gcov regexec.c
+ $ view regexec.c.gcov
+
=head2 Pixie Profiling
Pixie is a profiling tool available on IRIX and Tru64 (aka Digital
I'd now suggest you read over those references again, and then, as soon
as possible, get your hands dirty. The best way to learn is by doing,
-so:
+so:
=over 3