B::CC man page on HP-UX

Man page or keyword search:  
man Server   10987 pages
apropos Keyword Search (all sections)
Output format
HP-UX logo
[printable version]

B::CC(3)	       Perl Programmers Reference Guide		      B::CC(3)

       B::CC - Perl compiler's optimized C translation backend

	       perl -MO=CC[,OPTIONS] foo.pl

       This compiler backend takes Perl source and generates C source code
       corresponding to the flow of your program. In other words, this backend
       is somewhat a "real" compiler in the sense that many people think about
       compilers. Note however that, currently, it is a very poor compiler in
       that although it generates (mostly, or at least sometimes) correct
       code, it performs relatively few optimisations.	This will change as
       the compiler develops. The result is that running an executable com‐
       piled with this backend may start up more quickly than running the
       original Perl program (a feature shared by the C compiler backend--see
       B::C) and may also execute slightly faster. This is by no means a good
       optimising compiler--yet.

       If there are any non-option arguments, they are taken to be names of
       objects to be saved (probably doesn't work properly yet).  Without
       extra arguments, it saves the main program.

	   Output to filename instead of STDOUT

       -v  Verbose compilation (currently gives a few compilation statistics).

       --  Force end of options

	   Force apparently unused subs from package Packname to be compiled.
	   This allows programs to use eval "foo()" even when sub foo is never
	   seen to be used at compile time. The down side is that any subs
	   which really are never used also have code generated. This option
	   is necessary, for example, if you have a signal handler foo which
	   you initialise with "$SIG{BAR} = "foo"".  A better fix, though, is
	   just to change it to "$SIG{BAR} = \&foo". You can have multiple -u
	   options. The compiler tries to figure out which packages may possi‐
	   bly have subs in which need compiling but the current version
	   doesn't do it very well. In particular, it is confused by nested
	   packages (i.e.  of the form "A::B") where package "A" does not con‐
	   tain any subs.

	   Instead of generating source for a runnable executable, generate
	   source for an XSUB module. The boot_Modulename function (which
	   DynaLoader can look for) does the appropriate initialisation and
	   runs the main part of the Perl source that is being compiled.

       -D  Debug options (concatenated or separate flags like "perl -D").

       -Dr Writes debugging output to STDERR just as it's about to write to
	   the program's runtime (otherwise writes debugging info as comments
	   in its C output).

       -DO Outputs each OP as it's compiled

       -Ds Outputs the contents of the shadow stack at each OP

       -Dp Outputs the contents of the shadow pad of lexicals as it's loaded
	   for each sub or the main program.

       -Dq Outputs the name of each fake PP function in the queue as it's
	   about to process it.

       -Dl Output the filename and line number of each original line of Perl
	   code as it's processed ("pp_nextstate").

       -Dt Outputs timing information of compilation stages.

       -f  Force optimisations on or off one at a time.

	   Delays FREETMPS from the end of each statement to the end of the
	   each basic block.

	   Delays FREETMPS from the end of each statement to the end of the
	   group of basic blocks forming a loop. At most one of the
	   freetmps-each-* options can be used.

	   Omits generating code for handling perl's tainting mechanism.

       -On Optimisation level (n = 0, 1, 2, ...). -O means -O1.	 Currently,
	   -O1 sets -ffreetmps-each-bblock and -O2 sets -ffreetmps-each-loop.

	       perl -MO=CC,-O2,-ofoo.c foo.pl
	       perl cc_harness -o foo foo.c

       Note that "cc_harness" lives in the "B" subdirectory of your perl
       library directory. The utility called "perlcc" may also be used to help
       make use of this compiler.

	       perl -MO=CC,-mFoo,-oFoo.c Foo.pm
	       perl cc_harness -shared -c -o Foo.so Foo.c

       Plenty. Current status: experimental.

       These aren't really bugs but they are constructs which are heavily tied
       to perl's compile-and-go implementation and with which this compiler
       backend cannot cope.


       Standard perl calculates the target of "next", "last", and "redo" at
       run-time. The compiler calculates the targets at compile-time.  For
       example, the program

	   sub skip_on_odd { next NUMBER if $_[0] % 2 }
	   NUMBER: for ($i = 0; $i < 5; $i++) {
	       print $i;

       produces the output


       with standard perl but gives a compile-time error with the compiler.

       Context of ".."

       The context (scalar or array) of the ".." operator determines whether
       it behaves as a range or a flip/flop. Standard perl delays until run‐
       time the decision of which context it is in but the compiler needs to
       know the context at compile-time. For example,

	   @a = (4,6,1,0,0,1);
	   sub range { (shift @a)..(shift @a) }
	   print range();
	   while (@a) { print scalar(range()) }

       generates the output


       with standard Perl but gives a compile-time error with compiled Perl.


       Compiled Perl programs use native C arithmetic much more frequently
       than standard perl. Operations on large numbers or on boundary cases
       may produce different behaviour.

       Deprecated features

       Features of standard perl such as $[ which have been deprecated in
       standard perl since Perl5 was released have not been implemented in the

       Malcolm Beattie, "mbeattie@sable.ox.ac.uk"

perl v5.8.8			  2001-09-21			      B::CC(3)

List of man pages available for HP-UX

Copyright (c) for man pages and the logo by the respective OS vendor.

For those who want to learn more, the polarhome community provides shell access and support.

[legal] [privacy] [GNU] [policy] [cookies] [netiquette] [sponsors] [FAQ]
Polarhome, production since 1999.
Member of Polarhome portal.
Based on Fawad Halim's script.
Vote for polarhome
Free Shell Accounts :: the biggest list on the net