B::Xref(3) Perl Programmers Reference Guide B::Xref(3)NAMEB::Xref - Generates cross reference reports for Perl
programs
SYNOPSIS
perl -MO=Xref[,OPTIONS] foo.pl
DESCRIPTION
The B::Xref module is used to generate a cross reference
listing of all definitions and uses of variables,
subroutines and formats in a Perl program. It is
implemented as a backend for the Perl compiler.
The report generated is in the following format:
File filename1
Subroutine subname1
Package package1
object1 C<line numbers>
object2 C<line numbers>
...
Package package2
...
Each File section reports on a single file. Each
Subroutine section reports on a single subroutine apart
from the special cases "(definitions)" and "(main)". These
report, respectively, on subroutine definitions found by
the initial symbol table walk and on the main part of the
program or module external to all subroutines.
The report is then grouped by the Package of each
variable, subroutine or format with the special case
"(lexicals)" meaning lexical variables. Each object name
(implicitly qualified by its containing Package) includes
its type character(s) at the beginning where possible.
Lexical variables are easier to track and even included
dereferencing information where possible.
The line numbers are a comma separated list of line
numbers (some preceded by code letters) where that object
is used in some way. Simple uses aren't preceded by a
code letter. Introductions (such as where a lexical is
first defined with my) are indicated with the letter "i".
Subroutine and method calls are indicated by the character
"&". Subroutine definitions are indicated by "s" and
format definitions by "f".
OPTIONS
Option words are separated by commas (not whitespace) and
follow the usual conventions of compiler backend options.
-oFILENAME
Directs output to FILENAME instead of standard
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B::Xref(3) Perl Programmers Reference Guide B::Xref(3)
output.
-r Raw output. Instead of producing a human-readable
report, outputs a line in machine-readable form
for each definition/use of a variable/sub/format.
-D[tO] (Internal) debug options, probably only useful if
-r included. The t option prints the object on
the top of the stack as it's being tracked. The O
option prints each operator as it's being
processed in the execution order of the program.
BUGS
Non-lexical variables are quite difficult to track through
a program. Sometimes the type of a non-lexical variable's
use is impossible to determine. Introductions of non-
lexical non-scalars don't seem to be reported properly.
AUTHOR
Malcolm Beattie, mbeattie@sable.ox.ac.uk.
16/Sep/1999 perl 5.005, patch 03 2
