B::CC 5.8.8

B::CC is Perl compilers optimized C translation backend.

SYNOPSIS

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 compiled 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.

OPTIONS

If there are any non-option arguments, they are taken to be names of objects to be saved (probably doesnt 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 doesnt 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.

-mModulename

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 its about to write to the programs runtime (otherwise writes debugging info as comments in its C output).

-DO

Outputs each OP as its compiled

-Ds

Outputs the contents of the shadow stack at each OP

-Dp

Outputs the contents of the shadow pad of lexicals as its loaded for each sub or the main program.

-Dq

Outputs the name of each fake PP function in the queue as its about to process it.

-Dl

Output the filename and line number of each original line of Perl code as its processed (pp_nextstate).

-Dt

Outputs timing information of compilation stages.

-f

Force optimisations on or off one at a time.

-ffreetmps-each-bblock

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

-ffreetmps-each-loop

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.

-fomit-taint

Omits generating code for handling perls tainting mechanism.

-On

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