B::Xref - phpMan

NAME
    B::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        line numbers
              object2        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".

    For instance, here's part of the report from the *pod2man* program that
    comes with Perl:

      Subroutine clear_noremap
        Package (lexical)
          $ready_to_print   i1069, 1079
        Package main
          $&                1086
          $.                1086
          $0                1086
          $1                1087
          $2                1085, 1085
          $3                1085, 1085
          $ARGV             1086
          %HTML_Escapes     1085, 1085

    This shows the variables used in the subroutine "clear_noremap". The
    variable $ready_to_print is a my() (lexical) variable, introduced (first
    declared with my()) on line 1069, and used on line 1079. The variable $&
    from the main package is used on 1086, and so on.

    A line number may be prefixed by a single letter:

    i   Lexical variable introduced (declared with my()) for the first time.

    &   Subroutine or method call.

    s   Subroutine defined.

    r   Format defined.

    The most useful option the cross referencer has is to save the report to
    a separate file. For instance, to save the report on *myperlprogram* to
    the file *report*:

      $ perl -MO=Xref,-oreport myperlprogram

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 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"    Don't output the "(definitions)" sections.

    "-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 AT sable.uk.