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.
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 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.
-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 options/optimisations on or off one at a time. You can
explicitly disable an option using -fno-option. All options default
to disabled.
-fcog
Copy-on-grow: PVs declared and initialised statically.
-fsave-data
Save package::DATA filehandles ( only available with PerlIO ).
-fppaddr
Optimize the initialization of op_ppaddr.
-fwarn-sv
Optimize the initialization of cop_warnings.
-fuse-script-name
Use the script name instead of the program name as $0.
-fsave-sig-hash
Save compile-time modifications to the %SIG hash.
-On Optimisation level (n = 0, 1, 2, ...). -O means -O1.
-O0 Disable all optimizations.
-O1 Enable -fcog.
-O2 Enable -fppaddr, -fwarn-sv.
-llimit
Some C compilers impose an arbitrary limit on the length of string
constants (e.g. 2048 characters for Microsoft Visual C++). The
-llimit options tells the C backend not to generate string literals
exceeding that limit.
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,-l2048 bar.pl > /dev/null
BUGS
Plenty. Current status: experimental.
AUTHOR
Malcolm Beattie, "mbeattie@sable.ox.ac.uk"
perl v5.8.9 2001-09-21 B::C(3pm)
Mac OS X 10.6 - Generated Thu Sep 17 20:10:41 CDT 2009