Manual Pages for UNIX Darwin command on man B::C

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

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 environ-

ment in which your program runs this may be either a help or a hin-

drance. OOPPTTIIOONNSS

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.

-ooffiilleennaammee

Output to filename instead of STDOUT

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

-- Force end of options

-uuPPaacckknnaammee

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 -uu

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.

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

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

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

-DDAA prints AV information on saving

-DDCC prints CV information on saving

-DDMM prints MAGIC information on saving

-ff Force options/optimisations on or off one at a time. You can

explicitly disable an option using -ffnnoo-ooppttiioonn. All options default

to ddiissaabblleedd.

-ffccoogg

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

-ffssaavvee-ddaattaa

Save package::DATA filehandles ( only available with PerlIO ).

-ffppppaaddddrr

Optimize the initialization of opppaddr.

-ffwwaarrnn-ssvv

Optimize the initialization of copwarnings.

-ffuussee-ssccrriipptt-nnaammee

Use the script name instead of the program name as $0.

-ffssaavvee-ssiigg-hhaasshh

Save compile-time modifications to the %SIG hash.

-OOnn Optimisation level (n = 0, 1, 2, ...). -OO means -OO11.

-OO00 Disable all optimizations.

-OO11 Enable -ffccoogg.

-OO22 Enable -ffppppaaddddrr, -ffwwaarrnn-ssvv.

-lllliimmiitt

Some C compilers impose an arbitrary limit on the length of string constants (e.g. 2048 characters for Microsoft Visual C++). The

-lllliimmiitt options tells the C backend not to generate string literals

exceeding that limit. EEXXAAMMPPLLEESS

perl -MO=C,-ofoo.c foo.pl

perl ccharness -o foo foo.c

Note that "ccharness" 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,-l2048 bar.pl > /dev/null

BUGS

Plenty. Current status: experimental. AUTHOR Malcolm Beattie, "mbeattie@sable.ox.ac.uk"