/ 
B-Debugger-0.02
River stage zero No dependents
/ Od

NAME

Od - Idea of a Perl Compiler dump and debug

SYNOPSIS

perl -MOd=[-d=dump,]Backend[,OPTIONS] foo.pl
perl -d -MOd=Backend[,OPTIONS] foo.dump

DESCRIPTION

This module should be used as debugging replacement to O, the Perl Compiler frontend.

Debugging is done in two steps, first you store a optree dump in the CHECK stage into foo.dump, or the dumpfile specified with the -d=dump option, and the Compiler backend is never called.

Then you load the dump into the INIT stage and continue.

perl -d -MOd=Backend[,OPTIONS] foo.dump

Loads the stored optree after the CHECK stage, sets up the PL_main_root to point to the loaded optree dump and starts the debugger as specified via -d.

PROBLEMS

But than the nasty head of Storable and B appeared. B::OPs are a tree of linked pointers. So we need a walkoptree which stores all visited OPs into the Storable stream.

But then what to do in the 2nd thaw stage? B objects cannot be written to! All pointers are read-only. Storable hooks? Will fail on thaw. Looks like we need a B::OP::thaw method which re-creates blessed OPs and SVs with all its fields. Similar to Bytecode.

Setting up a dummy B package just for debugging makes no sense, as I want to debug the compiler which runs through a real B optree.

Oh my, so I gave up on this for this year.

AUTHOR

Reini Urban, rurban@cpan.org 2009