B::C

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



NAME
       B::C - Perl compiler's C backend

SYNOPSIS
               perl -MO=C[,OPTIONS] foo.pl


DESCRIPTION
       This compiler backend takes Perl source and generates C source code
       corresponding to the internal structures that perl uses to run your
       program. When the generated C source is compiled and run, it cuts out
       the time which perl would have taken to load and parse your program
       into its internal semi-compiled form. That means that compiling with
       this backend will not help improve the runtime execution speed of your
       program but may improve the start-up time.  Depending on the
       environment in which your program runs this may be either a help or a
       hindrance.

OPTIONS
       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.

       -ofilename
           Output to filename instead of STDOUT

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

       --  Force end of options

       -uPackname
           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
           possibly 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 contain
           any subs.

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

       -Do OPs, prints each OP as it's processed

       -Dc COPs, prints COPs as processed (incl. file & line num)

       -DA prints AV information on saving

       -DC prints CV information on saving

       -DM prints MAGIC information on saving

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

       -fcog
           Copy-on-grow: PVs declared and initialised statically.

       -fno-cog
           No copy-on-grow.

       -On Optimisation level (n = 0, 1, 2, ...). -O means -O1.  Currently,
           -O1 and higher set -fcog.

EXAMPLES
           perl -MO=C,-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=C,-v,-DcA bar.pl > /dev/null


BUGS
       Plenty. Current status: experimental.

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


























3rd Berkeley Distribution    perl 5.005, patch 02                      B::C(3)