right combination of C<const>s:
static const char * const yippee[] =
- {"hi", "ho", "silver"};
+ {"hi", "ho", "silver"};
There is a way to completely hide any modifiable globals (they are all
moved to heap), the compilation setting
-pedantic> flags which enforce stricter ANSI rules.
If using the C<gcc -Wall> note that not all the possible warnings (like
-C<-Wunitialized>) are given unless you also compile with C<-O>.
+C<-Wuninitialized>) are given unless you also compile with C<-O>.
Note that if using gcc, starting from Perl 5.9.5 the Perl core source
code files (the ones at the top level of the source code distribution,
Assuming one can dereference any type of pointer for any type of data
char *p = ...;
- long pony = *p; /* BAD */
+ long pony = *(long *)p; /* BAD */
Many platforms, quite rightly so, will give you a core dump instead of
a pony if the p happens not to be correctly aligned.
case alphabetic characters. That is not true in EBCDIC. Nor for 'a' to
'z'. But '0' - '9' is an unbroken range in both systems. Don't assume
anything about other ranges. (Note that special handling of ranges in
-regular expression patterns makes it appear to Perl
+regular expression patterns and transliterations makes it appear to Perl
code that the aforementioned ranges are all unbroken.)
Many of the comments in the existing code ignore the possibility of
printf("i = %"IVdf"\n", (IV)something_very_small_and_signed);
+See L<perlguts/Formatted Printing of Size_t and SSize_t> for how to
+print those.
+
Also remember that the C<%p> format really does require a void pointer:
U8* p = ...;
But in any case, try to keep the features and operating systems
separate.
+A good resource on the predefined macros for various operating
+systems, compilers, and so forth is
+L<http://sourceforge.net/p/predef/wiki/Home/>
+
=item *
Assuming the contents of static memory pointed to by the return values
To really poke around with Perl, you'll probably want to build Perl for
debugging, like this:
- ./Configure -d -D optimize=-g
+ ./Configure -d -DDEBUGGING
make
-C<-g> is a flag to the C compiler to have it produce debugging
-information which will allow us to step through a running program, and
-to see in which C function we are at (without the debugging information
-we might see only the numerical addresses of the functions, which is
-not very helpful).
-
-F<Configure> will also turn on the C<DEBUGGING> compilation symbol
-which enables all the internal debugging code in Perl. There are a
-whole bunch of things you can debug with this: L<perlrun> lists them
-all, and the best way to find out about them is to play about with
-them. The most useful options are probably
+C<-DDEBUGGING> turns on the C compiler's C<-g> flag to have it produce
+debugging information which will allow us to step through a running
+program, and to see in which C function we are at (without the debugging
+information we might see only the numerical addresses of the functions,
+which is not very helpful). It will also turn on the C<DEBUGGING>
+compilation symbol which enables all the internal debugging code in Perl.
+There are a whole bunch of things you can debug with this: L<perlrun>
+lists them all, and the best way to find out about them is to play about
+with them. The most useful options are probably
l Context (loop) stack processing
+ s Stack snapshots (with v, displays all stacks)
t Trace execution
o Method and overloading resolution
c String/numeric conversions
-Some of the functionality of the debugging code can be achieved using
-XS modules.
+For example
+
+ $ perl -Dst -e '$a + 1'
+ ....
+ (-e:1) gvsv(main::a)
+ => UNDEF
+ (-e:1) const(IV(1))
+ => UNDEF IV(1)
+ (-e:1) add
+ => NV(1)
+
+
+Some of the functionality of the debugging code can be achieved with a
+non-debugging perl by using XS modules:
-Dr => use re 'debug'
-Dx => use O 'Debug'
projects, and they give out accounts to open source developers to the
defect databases.
+There is Coverity setup for the perl5 project:
+L<https://scan.coverity.com/projects/perl5>
+
+=head2 HP-UX cadvise (Code Advisor)
+
+HP has a C/C++ static analyzer product for HP-UX caller Code Advisor.
+(Link not given here because the URL is horribly long and seems horribly
+unstable; use the search engine of your choice to find it.) The use of
+the C<cadvise_cc> recipe with C<Configure ... -Dcc=./cadvise_cc>
+(see cadvise "User Guide") is recommended; as is the use of C<+wall>.
+
=head2 cpd (cut-and-paste detector)
The cpd tool detects cut-and-paste coding. If one instance of the
does set this to 2, and this is what you need to do too, if you don't
want to see the "global leaks": For example, for running under valgrind
- env PERL_DESTRUCT_LEVEL=2 valgrind ./perl -Ilib t/foo/bar.t
+ env PERL_DESTRUCT_LEVEL=2 valgrind ./perl -Ilib t/foo/bar.t
(Note: the mod_perl apache module uses also this environment variable
for its own purposes and extended its semantics. Refer to the mod_perl
=head2 PERL_MEM_LOG
-If compiled with C<-DPERL_MEM_LOG>, both memory and SV allocations go
-through logging functions, which is handy for breakpoint setting.
+If compiled with C<-DPERL_MEM_LOG> (C<-Accflags=-DPERL_MEM_LOG>), both
+memory and SV allocations go through logging functions, which is
+handy for breakpoint setting.
-Unless C<-DPERL_MEM_LOG_NOIMPL> is also compiled, the logging functions
-read $ENV{PERL_MEM_LOG} to determine whether to log the event, and if
-so how:
+Unless C<-DPERL_MEM_LOG_NOIMPL> (C<-Accflags=-DPERL_MEM_LOG_NOIMPL>) is
+also compiled, the logging functions read $ENV{PERL_MEM_LOG} to
+determine whether to log the event, and if so how:
- $ENV{PERL_MEM_LOG} =~ /m/ Log all memory ops
- $ENV{PERL_MEM_LOG} =~ /s/ Log all SV ops
- $ENV{PERL_MEM_LOG} =~ /t/ include timestamp in Log
- $ENV{PERL_MEM_LOG} =~ /^(\d+)/ write to FD given (default is 2)
+ $ENV{PERL_MEM_LOG} =~ /m/ Log all memory ops
+ $ENV{PERL_MEM_LOG} =~ /s/ Log all SV ops
+ $ENV{PERL_MEM_LOG} =~ /t/ include timestamp in Log
+ $ENV{PERL_MEM_LOG} =~ /^(\d+)/ write to FD given (default is 2)
Memory logging is somewhat similar to C<-Dm> but is independent of
C<-DDEBUGGING>, and at a higher level; all uses of Newx(), Renew(), and
https://perl5.git.perl.org / perl5.git / blobdiff