b.pm

UNIX下perl实现代码

=item TARGLEN

=item TYPE

=item TARG

=back

=head2 B::BM METHODS

=over 4

=item USEFUL

=item PREVIOUS

=item RARE

=item TABLE

=back

=head2 B::GV METHODS

=over 4

=item is_empty

This method returns TRUE if the GP field of the GV is NULL.

=item NAME

=item SAFENAME

This method returns the name of the glob, but if the first
character of the name is a control character, then it converts
it to ^X first, so that *^G would return "^G" rather than "\cG".

It's useful if you want to print out the name of a variable.
If you restrict yourself to globs which exist at compile-time
then the result ought to be unambiguous, because code like
C<${"^G"} = 1> is compiled as two ops - a constant string and
a dereference (rv2gv) - so that the glob is created at runtime.

If you're working with globs at runtime, and need to disambiguate
*^G from *{"^G"}, then you should use the raw NAME method.

=item STASH

=item SV

=item IO

=item FORM

=item AV

=item HV

=item EGV

=item CV

=item CVGEN

=item LINE

=item FILE

=item FILEGV

=item GvREFCNT

=item FLAGS

=back

=head2 B::IO METHODS

=over 4

=item LINES

=item PAGE

=item PAGE_LEN

=item LINES_LEFT

=item TOP_NAME

=item TOP_GV

=item FMT_NAME

=item FMT_GV

=item BOTTOM_NAME

=item BOTTOM_GV

=item SUBPROCESS

=item IoTYPE

=item IoFLAGS

=back

=head2 B::AV METHODS

=over 4

=item FILL

=item MAX

=item OFF

=item ARRAY

=item AvFLAGS

=back

=head2 B::CV METHODS

=over 4

=item STASH

=item START

=item ROOT

=item GV

=item FILE

=item DEPTH

=item PADLIST

=item OUTSIDE

=item XSUB

=item XSUBANY

=item CvFLAGS

=back

=head2 B::HV METHODS

=over 4

=item FILL

=item MAX

=item KEYS

=item RITER

=item NAME

=item PMROOT

=item ARRAY

=back

=head2 OP-RELATED CLASSES

B::OP, B::UNOP, B::BINOP, B::LOGOP, B::LISTOP, B::PMOP,
B::SVOP, B::PADOP, B::PVOP, B::CVOP, B::LOOP, B::COP.
These classes correspond in
the obvious way to the underlying C structures of similar names. The
inheritance hierarchy mimics the underlying C "inheritance". Access
methods correspond to the underlying C structre field names, with the
leading "class indication" prefix removed (op_).

=head2 B::OP METHODS

=over 4

=item next

=item sibling

=item name

This returns the op name as a string (e.g. "add", "rv2av").

=item ppaddr

This returns the function name as a string (e.g. "PL_ppaddr[OP_ADD]",
"PL_ppaddr[OP_RV2AV]").

=item desc

This returns the op description from the global C PL_op_desc array
(e.g. "addition" "array deref").

=item targ

=item type

=item seq

=item flags

=item private

=back

=head2 B::UNOP METHOD

=over 4

=item first

=back

=head2 B::BINOP METHOD

=over 4

=item last

=back

=head2 B::LOGOP METHOD

=over 4

=item other

=back

=head2 B::LISTOP METHOD

=over 4

=item children

=back

=head2 B::PMOP METHODS

=over 4

=item pmreplroot

=item pmreplstart

=item pmnext

=item pmregexp

=item pmflags

=item pmpermflags

=item precomp

=back

=head2 B::SVOP METHOD

=over 4

=item sv

=item gv

=back

=head2 B::PADOP METHOD

=over 4

=item padix

=back

=head2 B::PVOP METHOD

=over 4

=item pv

=back

=head2 B::LOOP METHODS

=over 4

=item redoop

=item nextop

=item lastop

=back

=head2 B::COP METHODS

=over 4

=item label

=item stash

=item file

=item cop_seq

=item arybase

=item line

=back

=head1 FUNCTIONS EXPORTED BY C<B>

The C<B> module exports a variety of functions: some are simple
utility functions, others provide a Perl program with a way to
get an initial "handle" on an internal object.

=over 4

=item main_cv

Return the (faked) CV corresponding to the main part of the Perl
program.

=item init_av

Returns the AV object (i.e. in class B::AV) representing INIT blocks.

=item main_root

Returns the root op (i.e. an object in the appropriate B::OP-derived
class) of the main part of the Perl program.

=item main_start

Returns the starting op of the main part of the Perl program.

=item comppadlist

Returns the AV object (i.e. in class B::AV) of the global comppadlist.

=item sv_undef

Returns the SV object corresponding to the C variable C<sv_undef>.

=item sv_yes

Returns the SV object corresponding to the C variable C<sv_yes>.

=item sv_no

Returns the SV object corresponding to the C variable C<sv_no>.

=item amagic_generation

Returns the SV object corresponding to the C variable C<amagic_generation>.

=item walkoptree(OP, METHOD)

Does a tree-walk of the syntax tree based at OP and calls METHOD on
each op it visits. Each node is visited before its children. If
C<walkoptree_debug> (q.v.) has been called to turn debugging on then
the method C<walkoptree_debug> is called on each op before METHOD is
called.

=item walkoptree_debug(DEBUG)

Returns the current debugging flag for C<walkoptree>. If the optional
DEBUG argument is non-zero, it sets the debugging flag to that. See
the description of C<walkoptree> above for what the debugging flag
does.

=item walksymtable(SYMREF, METHOD, RECURSE)

Walk the symbol table starting at SYMREF and call METHOD on each
symbol visited. When the walk reached package symbols "Foo::" it
invokes RECURSE and only recurses into the package if that sub
returns true.

=item svref_2object(SV)

Takes any Perl variable and turns it into an object in the
appropriate B::OP-derived or B::SV-derived class. Apart from functions
such as C<main_root>, this is the primary way to get an initial
"handle" on a internal perl data structure which can then be followed
with the other access methods.

=item ppname(OPNUM)

Return the PP function name (e.g. "pp_add") of op number OPNUM.

=item hash(STR)

Returns a string in the form "0x..." representing the value of the
internal hash function used by perl on string STR.

=item cast_I32(I)

Casts I to the internal I32 type used by that perl.


=item minus_c

Does the equivalent of the C<-c> command-line option. Obviously, this
is only useful in a BEGIN block or else the flag is set too late.


=item cstring(STR)

Returns a double-quote-surrounded escaped version of STR which can
be used as a string in C source code.

=item class(OBJ)

Returns the class of an object without the part of the classname
preceding the first "::". This is used to turn "B::UNOP" into
"UNOP" for example.

=item threadsv_names

In a perl compiled for threads, this returns a list of the special
per-thread threadsv variables.

=back

=head1 AUTHOR

Malcolm Beattie, C<[e-mail]>

=cut