[perl5.git] / lib / ExtUtils / Mksymlists.pm

package ExtUtils::Mksymlists;

use 5.00503;
use strict qw[ subs refs ];
# no strict 'vars';  # until filehandles are exempted

use Carp;
use Exporter;
use Config;

use vars qw(@ISA @EXPORT $VERSION);
@ISA = 'Exporter';
@EXPORT = '&Mksymlists';
$VERSION = 1.19;

sub Mksymlists {
    my(%spec) = @_;
    my($osname) = $^O;

    croak("Insufficient information specified to Mksymlists")
        unless ( $spec{NAME} or
                 ($spec{FILE} and ($spec{DL_FUNCS} or $spec{FUNCLIST})) );

    $spec{DL_VARS} = [] unless $spec{DL_VARS};
    ($spec{FILE} = $spec{NAME}) =~ s/.*::// unless $spec{FILE};
    $spec{FUNCLIST} = [] unless $spec{FUNCLIST};
    $spec{DL_FUNCS} = { $spec{NAME} => [] }
        unless ( ($spec{DL_FUNCS} and keys %{$spec{DL_FUNCS}}) or
                 @{$spec{FUNCLIST}});
    if (defined $spec{DL_FUNCS}) {
        my($package);
        foreach $package (keys %{$spec{DL_FUNCS}}) {
            my($packprefix,$sym,$bootseen);
            ($packprefix = $package) =~ s/\W/_/g;
            foreach $sym (@{$spec{DL_FUNCS}->{$package}}) {
                if ($sym =~ /^boot_/) {
                    push(@{$spec{FUNCLIST}},$sym);
                    $bootseen++;
                }
                else { push(@{$spec{FUNCLIST}},"XS_${packprefix}_$sym"); }
            }
            push(@{$spec{FUNCLIST}},"boot_$packprefix") unless $bootseen;
        }
    }

#    We'll need this if we ever add any OS which uses mod2fname
#    not as pseudo-builtin.
#    require DynaLoader;
    if (defined &DynaLoader::mod2fname and not $spec{DLBASE}) {
        $spec{DLBASE} = DynaLoader::mod2fname([ split(/::/,$spec{NAME}) ]);
    }

    if    ($osname eq 'aix') { _write_aix(\%spec); }
    elsif ($osname eq 'MacOS'){ _write_aix(\%spec) }
    elsif ($osname eq 'VMS') { _write_vms(\%spec) }
    elsif ($osname eq 'os2') { _write_os2(\%spec) }
    elsif ($osname eq 'MSWin32') { _write_win32(\%spec) }
    else { croak("Don't know how to create linker option file for $osname\n"); }
}


sub _write_aix {
    my($data) = @_;

    rename "$data->{FILE}.exp", "$data->{FILE}.exp_old";

    open(EXP,">$data->{FILE}.exp")
        or croak("Can't create $data->{FILE}.exp: $!\n");
    print EXP join("\n",@{$data->{DL_VARS}}, "\n") if @{$data->{DL_VARS}};
    print EXP join("\n",@{$data->{FUNCLIST}}, "\n") if @{$data->{FUNCLIST}};
    close EXP;
}


sub _write_os2 {
    my($data) = @_;
    require Config;
    my $threaded = ($Config::Config{archname} =~ /-thread/ ? " threaded" : "");

    if (not $data->{DLBASE}) {
        ($data->{DLBASE} = $data->{NAME}) =~ s/.*:://;
        $data->{DLBASE} = substr($data->{DLBASE},0,7) . '_';
    }
    my $distname = $data->{DISTNAME} || $data->{NAME};
    $distname = "Distribution $distname";
    my $patchlevel = " pl$Config{perl_patchlevel}" || '';
    my $comment = sprintf "Perl (v%s%s%s) module %s", 
      $Config::Config{version}, $threaded, $patchlevel, $data->{NAME};
    chomp $comment;
    if ($data->{INSTALLDIRS} and $data->{INSTALLDIRS} eq 'perl') {
	$distname = 'perl5-porters@perl.org';
	$comment = "Core $comment";
    }
    $comment = "$comment (Perl-config: $Config{config_args})";
    $comment = substr($comment, 0, 200) . "...)" if length $comment > 203;
    rename "$data->{FILE}.def", "$data->{FILE}_def.old";

    open(DEF,">$data->{FILE}.def")
        or croak("Can't create $data->{FILE}.def: $!\n");
    print DEF "LIBRARY '$data->{DLBASE}' INITINSTANCE TERMINSTANCE\n";
    print DEF "DESCRIPTION '\@#$distname:$data->{VERSION}#\@ $comment'\n";
    print DEF "CODE LOADONCALL\n";
    print DEF "DATA LOADONCALL NONSHARED MULTIPLE\n";
    print DEF "EXPORTS\n  ";
    print DEF join("\n  ",@{$data->{DL_VARS}}, "\n") if @{$data->{DL_VARS}};
    print DEF join("\n  ",@{$data->{FUNCLIST}}, "\n") if @{$data->{FUNCLIST}};
    if (%{$data->{IMPORTS}}) {
        print DEF "IMPORTS\n";
	my ($name, $exp);
	while (($name, $exp)= each %{$data->{IMPORTS}}) {
	    print DEF "  $name=$exp\n";
	}
    }
    close DEF;
}

sub _write_win32 {
    my($data) = @_;

    require Config;
    if (not $data->{DLBASE}) {
        ($data->{DLBASE} = $data->{NAME}) =~ s/.*:://;
        $data->{DLBASE} = substr($data->{DLBASE},0,7) . '_';
    }
    rename "$data->{FILE}.def", "$data->{FILE}_def.old";

    open(DEF,">$data->{FILE}.def")
        or croak("Can't create $data->{FILE}.def: $!\n");
    # put library name in quotes (it could be a keyword, like 'Alias')
    if ($Config::Config{'cc'} !~ /^gcc/i) {
      print DEF "LIBRARY \"$data->{DLBASE}\"\n";
    }
    print DEF "EXPORTS\n  ";
    my @syms;
    # Export public symbols both with and without underscores to
    # ensure compatibility between DLLs from different compilers
    # NOTE: DynaLoader itself only uses the names without underscores,
    # so this is only to cover the case when the extension DLL may be
    # linked to directly from C. GSAR 97-07-10
    if ($Config::Config{'cc'} =~ /^bcc/i) {
	for (@{$data->{DL_VARS}}, @{$data->{FUNCLIST}}) {
	    push @syms, "_$_", "$_ = _$_";
	}
    }
    else {
	for (@{$data->{DL_VARS}}, @{$data->{FUNCLIST}}) {
	    push @syms, "$_", "_$_ = $_";
	}
    }
    print DEF join("\n  ",@syms, "\n") if @syms;
    if (%{$data->{IMPORTS}}) {
        print DEF "IMPORTS\n";
        my ($name, $exp);
        while (($name, $exp)= each %{$data->{IMPORTS}}) {
            print DEF "  $name=$exp\n";
        }
    }
    close DEF;
}


sub _write_vms {
    my($data) = @_;

    require Config; # a reminder for once we do $^O
    require ExtUtils::XSSymSet;

    my($isvax) = $Config::Config{'archname'} =~ /VAX/i;
    my($set) = new ExtUtils::XSSymSet;
    my($sym);

    rename "$data->{FILE}.opt", "$data->{FILE}.opt_old";

    open(OPT,">$data->{FILE}.opt")
        or croak("Can't create $data->{FILE}.opt: $!\n");

    # Options file declaring universal symbols
    # Used when linking shareable image for dynamic extension,
    # or when linking PerlShr into which we've added this package
    # as a static extension
    # We don't do anything to preserve order, so we won't relax
    # the GSMATCH criteria for a dynamic extension

    print OPT "case_sensitive=yes\n"
        if $Config::Config{d_vms_case_sensitive_symbols};
    foreach $sym (@{$data->{FUNCLIST}}) {
        my $safe = $set->addsym($sym);
        if ($isvax) { print OPT "UNIVERSAL=$safe\n" }
        else        { print OPT "SYMBOL_VECTOR=($safe=PROCEDURE)\n"; }
    }
    foreach $sym (@{$data->{DL_VARS}}) {
        my $safe = $set->addsym($sym);
        print OPT "PSECT_ATTR=${sym},PIC,OVR,RD,NOEXE,WRT,NOSHR\n";
        if ($isvax) { print OPT "UNIVERSAL=$safe\n" }
        else        { print OPT "SYMBOL_VECTOR=($safe=DATA)\n"; }
    }
    close OPT;

}

1;

__END__

=head1 NAME

ExtUtils::Mksymlists - write linker options files for dynamic extension

=head1 SYNOPSIS

    use ExtUtils::Mksymlists;
    Mksymlists({ NAME     => $name ,
                 DL_VARS  => [ $var1, $var2, $var3 ],
                 DL_FUNCS => { $pkg1 => [ $func1, $func2 ],
                               $pkg2 => [ $func3 ] });

=head1 DESCRIPTION

C<ExtUtils::Mksymlists> produces files used by the linker under some OSs
during the creation of shared libraries for dynamic extensions.  It is
normally called from a MakeMaker-generated Makefile when the extension
is built.  The linker option file is generated by calling the function
C<Mksymlists>, which is exported by default from C<ExtUtils::Mksymlists>.
It takes one argument, a list of key-value pairs, in which the following
keys are recognized:

=over 4

=item DLBASE

This item specifies the name by which the linker knows the
extension, which may be different from the name of the
extension itself (for instance, some linkers add an '_' to the
name of the extension).  If it is not specified, it is derived
from the NAME attribute.  It is presently used only by OS2 and Win32.

=item DL_FUNCS

This is identical to the DL_FUNCS attribute available via MakeMaker,
from which it is usually taken.  Its value is a reference to an
associative array, in which each key is the name of a package, and
each value is an a reference to an array of function names which
should be exported by the extension.  For instance, one might say
C<DL_FUNCS =E<gt> { Homer::Iliad =E<gt> [ qw(trojans greeks) ],
Homer::Odyssey =E<gt> [ qw(travellers family suitors) ] }>.  The
function names should be identical to those in the XSUB code;
C<Mksymlists> will alter the names written to the linker option
file to match the changes made by F<xsubpp>.  In addition, if
none of the functions in a list begin with the string B<boot_>,
C<Mksymlists> will add a bootstrap function for that package,
just as xsubpp does.  (If a B<boot_E<lt>pkgE<gt>> function is
present in the list, it is passed through unchanged.)  If
DL_FUNCS is not specified, it defaults to the bootstrap
function for the extension specified in NAME.

=item DL_VARS

This is identical to the DL_VARS attribute available via MakeMaker,
and, like DL_FUNCS, it is usually specified via MakeMaker.  Its
value is a reference to an array of variable names which should
be exported by the extension.

=item FILE

This key can be used to specify the name of the linker option file
(minus the OS-specific extension), if for some reason you do not
want to use the default value, which is the last word of the NAME
attribute (I<e.g.> for C<Tk::Canvas>, FILE defaults to C<Canvas>).

=item FUNCLIST

This provides an alternate means to specify function names to be
exported from the extension.  Its value is a reference to an
array of function names to be exported by the extension.  These
names are passed through unaltered to the linker options file.
Specifying a value for the FUNCLIST attribute suppresses automatic
generation of the bootstrap function for the package. To still create
the bootstrap name you have to specify the package name in the
DL_FUNCS hash:

    Mksymlists({ NAME     => $name ,
		 FUNCLIST => [ $func1, $func2 ],
                 DL_FUNCS => { $pkg => [] } });


=item IMPORTS

This attribute is used to specify names to be imported into the
extension. It is currently only used by OS/2 and Win32.

=item NAME

This gives the name of the extension (I<e.g.> C<Tk::Canvas>) for which
the linker option file will be produced.

=back

When calling C<Mksymlists>, one should always specify the NAME
attribute.  In most cases, this is all that's necessary.  In
the case of unusual extensions, however, the other attributes
can be used to provide additional information to the linker.

=head1 AUTHOR

Charles Bailey I<E<lt>bailey@newman.upenn.eduE<gt>>

=head1 REVISION

Last revised 14-Feb-1996, for Perl 5.002.
Commit	Line	Data
c07a80fd	1	package ExtUtils::Mksymlists;
cb50131a	2
57b1a898	3	use 5.00503;
c07a80fd	4	use strict qw[ subs refs ];
	5	# no strict 'vars'; # until filehandles are exempted
	6
	7	use Carp;
c07a80fd	8	use Exporter;
1102eebe	9	use Config;
57b1a898 MS	10
57b1a898 MS	11	use vars qw(@ISA @EXPORT $VERSION);
f1387719	12	@ISA = 'Exporter';
f1387719	13	@EXPORT = '&Mksymlists';
69ff8adf	14	$VERSION = 1.19;
c07a80fd	15
	16	sub Mksymlists {
	17	my(%spec) = @_;
f1387719	18	my($osname) = $^O;
c07a80fd	19
	20	croak("Insufficient information specified to Mksymlists")
	21	unless ( $spec{NAME} or
	22	($spec{FILE} and ($spec{DL_FUNCS} or $spec{FUNCLIST})) );
	23
	24	$spec{DL_VARS} = [] unless $spec{DL_VARS};
	25	($spec{FILE} = $spec{NAME}) =~ s/.*::// unless $spec{FILE};
348844dc	26	$spec{FUNCLIST} = [] unless $spec{FUNCLIST};
c07a80fd	27	$spec{DL_FUNCS} = { $spec{NAME} => [] }
c07a80fd	28	unless ( ($spec{DL_FUNCS} and keys %{$spec{DL_FUNCS}}) or
348844dc	29	@{$spec{FUNCLIST}});
c07a80fd	30	if (defined $spec{DL_FUNCS}) {
	31	my($package);
	32	foreach $package (keys %{$spec{DL_FUNCS}}) {
	33	my($packprefix,$sym,$bootseen);
	34	($packprefix = $package) =~ s/\W/_/g;
	35	foreach $sym (@{$spec{DL_FUNCS}->{$package}}) {
	36	if ($sym =~ /^boot_/) {
	37	push(@{$spec{FUNCLIST}},$sym);
	38	$bootseen++;
	39	}
	40	else { push(@{$spec{FUNCLIST}},"XS_${packprefix}_$sym"); }
	41	}
	42	push(@{$spec{FUNCLIST}},"boot_$packprefix") unless $bootseen;
	43	}
	44	}
	45
	46	# We'll need this if we ever add any OS which uses mod2fname
760ac839	47	# not as pseudo-builtin.
c07a80fd	48	# require DynaLoader;
c2e89b3d	49	if (defined &DynaLoader::mod2fname and not $spec{DLBASE}) {
	50	$spec{DLBASE} = DynaLoader::mod2fname([ split(/::/,$spec{NAME}) ]);
	51	}
c07a80fd	52
f1387719	53	if ($osname eq 'aix') { _write_aix(\%spec); }
6d697788	54	elsif ($osname eq 'MacOS'){ _write_aix(\%spec) }
f1387719	55	elsif ($osname eq 'VMS') { _write_vms(\%spec) }
bab2b58e	56	elsif ($osname eq 'os2') { _write_os2(\%spec) }
68dc0745	57	elsif ($osname eq 'MSWin32') { _write_win32(\%spec) }
f1387719	58	else { croak("Don't know how to create linker option file for $osname\n"); }
c07a80fd	59	}
	60
	61
	62	sub _write_aix {
	63	my($data) = @_;
	64
	65	rename "$data->{FILE}.exp", "$data->{FILE}.exp_old";
	66
	67	open(EXP,">$data->{FILE}.exp")
	68	or croak("Can't create $data->{FILE}.exp: $!\n");
	69	print EXP join("\n",@{$data->{DL_VARS}}, "\n") if @{$data->{DL_VARS}};
	70	print EXP join("\n",@{$data->{FUNCLIST}}, "\n") if @{$data->{FUNCLIST}};
	71	close EXP;
	72	}
	73
	74
	75	sub _write_os2 {
	76	my($data) = @_;
6ee623d5 GS	77	require Config;
6ee623d5 GS	78	my $threaded = ($Config::Config{archname} =~ /-thread/ ? " threaded" : "");
c07a80fd	79
	80	if (not $data->{DLBASE}) {
	81	($data->{DLBASE} = $data->{NAME}) =~ s/.*:://;
	82	$data->{DLBASE} = substr($data->{DLBASE},0,7) . '_';
	83	}
3cfae81b IZ	84	my $distname = $data->{DISTNAME} \|\| $data->{NAME};
3cfae81b IZ	85	$distname = "Distribution $distname";
f6d6199c MS	86	my $patchlevel = " pl$Config{perl_patchlevel}" \|\| '';
	87	my $comment = sprintf "Perl (v%s%s%s) module %s",
	88	$Config::Config{version}, $threaded, $patchlevel, $data->{NAME};
52e4c282	89	chomp $comment;
3cfae81b IZ	90	if ($data->{INSTALLDIRS} and $data->{INSTALLDIRS} eq 'perl') {
	91	$distname = 'perl5-porters@perl.org';
	92	$comment = "Core $comment";
	93	}
1102eebe IZ	94	$comment = "$comment (Perl-config: $Config{config_args})";
1102eebe IZ	95	$comment = substr($comment, 0, 200) . "...)" if length $comment > 203;
c07a80fd	96	rename "$data->{FILE}.def", "$data->{FILE}_def.old";
	97
	98	open(DEF,">$data->{FILE}.def")
	99	or croak("Can't create $data->{FILE}.def: $!\n");
	100	print DEF "LIBRARY '$data->{DLBASE}' INITINSTANCE TERMINSTANCE\n";
3cfae81b	101	print DEF "DESCRIPTION '\@#$distname:$data->{VERSION}#\@ $comment'\n";
c07a80fd	102	print DEF "CODE LOADONCALL\n";
c07a80fd	103	print DEF "DATA LOADONCALL NONSHARED MULTIPLE\n";
c2e89b3d	104	print DEF "EXPORTS\n ";
	105	print DEF join("\n ",@{$data->{DL_VARS}}, "\n") if @{$data->{DL_VARS}};
	106	print DEF join("\n ",@{$data->{FUNCLIST}}, "\n") if @{$data->{FUNCLIST}};
	107	if (%{$data->{IMPORTS}}) {
	108	print DEF "IMPORTS\n";
875fa795 JD	109	my ($name, $exp);
	110	while (($name, $exp)= each %{$data->{IMPORTS}}) {
	111	print DEF " $name=$exp\n";
	112	}
c2e89b3d	113	}
c07a80fd	114	close DEF;
	115	}
	116
68dc0745	117	sub _write_win32 {
	118	my($data) = @_;
	119
3e3baf6d	120	require Config;
68dc0745	121	if (not $data->{DLBASE}) {
	122	($data->{DLBASE} = $data->{NAME}) =~ s/.*:://;
	123	$data->{DLBASE} = substr($data->{DLBASE},0,7) . '_';
	124	}
	125	rename "$data->{FILE}.def", "$data->{FILE}_def.old";
	126
	127	open(DEF,">$data->{FILE}.def")
	128	or croak("Can't create $data->{FILE}.def: $!\n");
84902520	129	# put library name in quotes (it could be a keyword, like 'Alias')
5b0d9cbe NIS	130	if ($Config::Config{'cc'} !~ /^gcc/i) {
5b0d9cbe NIS	131	print DEF "LIBRARY \"$data->{DLBASE}\"\n";
5b0d9cbe	132	}
68dc0745	133	print DEF "EXPORTS\n ";
84902520 TB	134	my @syms;
	135	# Export public symbols both with and without underscores to
	136	# ensure compatibility between DLLs from different compilers
	137	# NOTE: DynaLoader itself only uses the names without underscores,
	138	# so this is only to cover the case when the extension DLL may be
	139	# linked to directly from C. GSAR 97-07-10
3e3baf6d	140	if ($Config::Config{'cc'} =~ /^bcc/i) {
84902520 TB	141	for (@{$data->{DL_VARS}}, @{$data->{FUNCLIST}}) {
	142	push @syms, "_$_", "$_ = _$_";
	143	}
3e3baf6d	144	}
84902520 TB	145	else {
	146	for (@{$data->{DL_VARS}}, @{$data->{FUNCLIST}}) {
	147	push @syms, "$_", "_$_ = $_";
	148	}
	149	}
	150	print DEF join("\n ",@syms, "\n") if @syms;
68dc0745	151	if (%{$data->{IMPORTS}}) {
	152	print DEF "IMPORTS\n";
	153	my ($name, $exp);
	154	while (($name, $exp)= each %{$data->{IMPORTS}}) {
	155	print DEF " $name=$exp\n";
	156	}
	157	}
	158	close DEF;
	159	}
	160
c07a80fd	161
	162	sub _write_vms {
	163	my($data) = @_;
a6e61155	164
f1387719	165	require Config; # a reminder for once we do $^O
ff0cee69	166	require ExtUtils::XSSymSet;
a6e61155	167
8c99d73e	168	my($isvax) = $Config::Config{'archname'} =~ /VAX/i;
ff0cee69	169	my($set) = new ExtUtils::XSSymSet;
c07a80fd	170	my($sym);
	171
	172	rename "$data->{FILE}.opt", "$data->{FILE}.opt_old";
	173
	174	open(OPT,">$data->{FILE}.opt")
	175	or croak("Can't create $data->{FILE}.opt: $!\n");
	176
	177	# Options file declaring universal symbols
	178	# Used when linking shareable image for dynamic extension,
	179	# or when linking PerlShr into which we've added this package
	180	# as a static extension
	181	# We don't do anything to preserve order, so we won't relax
	182	# the GSMATCH criteria for a dynamic extension
	183
80601f72 CB	184	print OPT "case_sensitive=yes\n"
80601f72 CB	185	if $Config::Config{d_vms_case_sensitive_symbols};
c07a80fd	186	foreach $sym (@{$data->{FUNCLIST}}) {
ff0cee69	187	my $safe = $set->addsym($sym);
	188	if ($isvax) { print OPT "UNIVERSAL=$safe\n" }
	189	else { print OPT "SYMBOL_VECTOR=($safe=PROCEDURE)\n"; }
c07a80fd	190	}
c07a80fd	191	foreach $sym (@{$data->{DL_VARS}}) {
ff0cee69	192	my $safe = $set->addsym($sym);
c07a80fd	193	print OPT "PSECT_ATTR=${sym},PIC,OVR,RD,NOEXE,WRT,NOSHR\n";
ff0cee69	194	if ($isvax) { print OPT "UNIVERSAL=$safe\n" }
ff0cee69	195	else { print OPT "SYMBOL_VECTOR=($safe=DATA)\n"; }
c07a80fd	196	}
	197	close OPT;
	198
c07a80fd	199	}
	200
	201	1;
	202
	203	__END__
	204
	205	=head1 NAME
	206
	207	ExtUtils::Mksymlists - write linker options files for dynamic extension
	208
	209	=head1 SYNOPSIS
	210
	211	use ExtUtils::Mksymlists;
	212	Mksymlists({ NAME => $name ,
	213	DL_VARS => [ $var1, $var2, $var3 ],
	214	DL_FUNCS => { $pkg1 => [ $func1, $func2 ],
	215	$pkg2 => [ $func3 ] });
	216
	217	=head1 DESCRIPTION
	218
	219	C<ExtUtils::Mksymlists> produces files used by the linker under some OSs
1fef88e7	220	during the creation of shared libraries for dynamic extensions. It is
c07a80fd	221	normally called from a MakeMaker-generated Makefile when the extension
	222	is built. The linker option file is generated by calling the function
	223	C<Mksymlists>, which is exported by default from C<ExtUtils::Mksymlists>.
	224	It takes one argument, a list of key-value pairs, in which the following
	225	keys are recognized:
	226
bbc7dcd2	227	=over 4
2ae324a7	228
875fa795	229	=item DLBASE
c07a80fd	230
875fa795 JD	231	This item specifies the name by which the linker knows the
	232	extension, which may be different from the name of the
	233	extension itself (for instance, some linkers add an '_' to the
	234	name of the extension). If it is not specified, it is derived
	235	from the NAME attribute. It is presently used only by OS2 and Win32.
c07a80fd	236
	237	=item DL_FUNCS
	238
	239	This is identical to the DL_FUNCS attribute available via MakeMaker,
	240	from which it is usually taken. Its value is a reference to an
	241	associative array, in which each key is the name of a package, and
	242	each value is an a reference to an array of function names which
	243	should be exported by the extension. For instance, one might say
875fa795	244	C<DL_FUNCS =E<gt> { Homer::Iliad =E<gt> [ qw(trojans greeks) ],
a5f75d66	245	Homer::Odyssey =E<gt> [ qw(travellers family suitors) ] }>. The
c07a80fd	246	function names should be identical to those in the XSUB code;
	247	C<Mksymlists> will alter the names written to the linker option
	248	file to match the changes made by F<xsubpp>. In addition, if
	249	none of the functions in a list begin with the string B<boot_>,
	250	C<Mksymlists> will add a bootstrap function for that package,
	251	just as xsubpp does. (If a B<boot_E<lt>pkgE<gt>> function is
	252	present in the list, it is passed through unchanged.) If
	253	DL_FUNCS is not specified, it defaults to the bootstrap
	254	function for the extension specified in NAME.
	255
	256	=item DL_VARS
	257
	258	This is identical to the DL_VARS attribute available via MakeMaker,
	259	and, like DL_FUNCS, it is usually specified via MakeMaker. Its
	260	value is a reference to an array of variable names which should
	261	be exported by the extension.
	262
	263	=item FILE
	264
	265	This key can be used to specify the name of the linker option file
	266	(minus the OS-specific extension), if for some reason you do not
	267	want to use the default value, which is the last word of the NAME
875fa795	268	attribute (I<e.g.> for C<Tk::Canvas>, FILE defaults to C<Canvas>).
c07a80fd	269
	270	=item FUNCLIST
	271
	272	This provides an alternate means to specify function names to be
	273	exported from the extension. Its value is a reference to an
	274	array of function names to be exported by the extension. These
	275	names are passed through unaltered to the linker options file.
de592821	276	Specifying a value for the FUNCLIST attribute suppresses automatic
875fa795 JD	277	generation of the bootstrap function for the package. To still create
	278	the bootstrap name you have to specify the package name in the
	279	DL_FUNCS hash:
c07a80fd	280
875fa795 JD	281	Mksymlists({ NAME => $name ,
	282	FUNCLIST => [ $func1, $func2 ],
	283	DL_FUNCS => { $pkg => [] } });
c07a80fd	284
875fa795 JD	285
	286	=item IMPORTS
	287
	288	This attribute is used to specify names to be imported into the
	289	extension. It is currently only used by OS/2 and Win32.
	290
	291	=item NAME
	292
	293	This gives the name of the extension (I<e.g.> C<Tk::Canvas>) for which
	294	the linker option file will be produced.
c07a80fd	295
2ae324a7	296	=back
2ae324a7	297
c07a80fd	298	When calling C<Mksymlists>, one should always specify the NAME
	299	attribute. In most cases, this is all that's necessary. In
	300	the case of unusual extensions, however, the other attributes
	301	can be used to provide additional information to the linker.
	302
	303	=head1 AUTHOR
	304
bd3fa61c	305	Charles Bailey I<E<lt>bailey@newman.upenn.eduE<gt>>
c07a80fd	306
	307	=head1 REVISION
	308
a5f75d66	309	Last revised 14-Feb-1996, for Perl 5.002.