Current File : //usr/lib/x86_64-linux-gnu/perl-base/DynaLoader.pm
# Generated from DynaLoader_pm.PL, this file is unique for every OS
use strict;
package DynaLoader;
# And Gandalf said: 'Many folk like to know beforehand what is to
# be set on the table; but those who have laboured to prepare the
# feast like to keep their secret; for wonder makes the words of
# praise louder.'
# (Quote from Tolkien suggested by Anno Siegel.)
#
# See pod text at end of file for documentation.
# See also ext/DynaLoader/README in source tree for other information.
#
# Tim.Bunce@ig.co.uk, August 1994
BEGIN {
our $VERSION = '1.54';
}
# Note: in almost any other piece of code "our" would have been a better
# option than "use vars", but DynaLoader's bootstrap files need the
# side effect of the variable being declared in any scope whose current
# package is DynaLoader, not just the current lexical one.
use vars qw(@dl_library_path @dl_resolve_using @dl_require_symbols
$dl_debug @dl_librefs @dl_modules @dl_shared_objects
$dl_dlext $dl_so $dlsrc @args $module @dirs $file $bscode);
use Config;
# enable debug/trace messages from DynaLoader perl code
$dl_debug = $ENV{PERL_DL_DEBUG} || 0 unless defined $dl_debug;
#
# Flags to alter dl_load_file behaviour. Assigned bits:
# 0x01 make symbols available for linking later dl_load_file's.
# (only known to work on Solaris 2 using dlopen(RTLD_GLOBAL))
# (ignored under VMS; effect is built-in to image linking)
# (ignored under Android; the linker always uses RTLD_LOCAL)
#
# This is called as a class method $module->dl_load_flags. The
# definition here will be inherited and result on "default" loading
# behaviour unless a sub-class of DynaLoader defines its own version.
#
sub dl_load_flags { 0x00 }
($dl_dlext, $dl_so, $dlsrc) = @Config::Config{qw(dlext so dlsrc)};
# Some systems need special handling to expand file specifications
# (VMS support by Charles Bailey <bailey@HMIVAX.HUMGEN.UPENN.EDU>)
# See dl_expandspec() for more details. Should be harmless but
# inefficient to define on systems that don't need it.
my $do_expand = 0;
@dl_require_symbols = (); # names of symbols we need
@dl_library_path = (); # path to look for files
#XSLoader.pm may have added elements before we were required
#@dl_shared_objects = (); # shared objects for symbols we have
#@dl_librefs = (); # things we have loaded
#@dl_modules = (); # Modules we have loaded
# Initialise @dl_library_path with the 'standard' library path
# for this platform as determined by Configure.
push(@dl_library_path, split(' ', $Config::Config{libpth}));
my $ldlibpthname = $Config::Config{ldlibpthname};
my $ldlibpthname_defined = defined $Config::Config{ldlibpthname};
my $pthsep = $Config::Config{path_sep};
# Add to @dl_library_path any extra directories we can gather from environment
# during runtime.
if ($ldlibpthname_defined &&
exists $ENV{$ldlibpthname}) {
push(@dl_library_path, split(/$pthsep/, $ENV{$ldlibpthname}));
}
# E.g. HP-UX supports both its native SHLIB_PATH *and* LD_LIBRARY_PATH.
if ($ldlibpthname_defined &&
$ldlibpthname ne 'LD_LIBRARY_PATH' &&
exists $ENV{LD_LIBRARY_PATH}) {
push(@dl_library_path, split(/$pthsep/, $ENV{LD_LIBRARY_PATH}));
}
# No prizes for guessing why we don't say 'bootstrap DynaLoader;' here.
# NOTE: All dl_*.xs (including dl_none.xs) define a dl_error() XSUB
boot_DynaLoader('DynaLoader') if defined(&boot_DynaLoader) &&
!defined(&dl_error);
if ($dl_debug) {
print STDERR "DynaLoader.pm loaded (@INC, @dl_library_path)\n";
print STDERR "DynaLoader not linked into this perl\n"
unless defined(&boot_DynaLoader);
}
1; # End of main code
sub croak { require Carp; Carp::croak(@_) }
sub bootstrap_inherit {
my $module = $_[0];
no strict qw/refs vars/;
local *isa = *{"$module\::ISA"};
local @isa = (@isa, 'DynaLoader');
# Cannot goto due to delocalization. Will report errors on a wrong line?
bootstrap(@_);
}
sub bootstrap {
# use local vars to enable $module.bs script to edit values
local(@args) = @_;
local($module) = $args[0];
local(@dirs, $file);
unless ($module) {
require Carp;
Carp::confess("Usage: DynaLoader::bootstrap(module)");
}
# A common error on platforms which don't support dynamic loading.
# Since it's fatal and potentially confusing we give a detailed message.
croak("Can't load module $module, dynamic loading not available in this perl.\n".
" (You may need to build a new perl executable which either supports\n".
" dynamic loading or has the $module module statically linked into it.)\n")
unless defined(&dl_load_file);
my @modparts = split(/::/,$module);
my $modfname = $modparts[-1];
my $modfname_orig = $modfname; # For .bs file search
# Some systems have restrictions on files names for DLL's etc.
# mod2fname returns appropriate file base name (typically truncated)
# It may also edit @modparts if required.
$modfname = &mod2fname(\@modparts) if defined &mod2fname;
my $modpname = join('/',@modparts);
print STDERR "DynaLoader::bootstrap for $module ",
"(auto/$modpname/$modfname.$dl_dlext)\n"
if $dl_debug;
my $dir;
foreach (@INC) {
$dir = "$_/auto/$modpname";
next unless -d $dir; # skip over uninteresting directories
# check for common cases to avoid autoload of dl_findfile
my $try = "$dir/$modfname.$dl_dlext";
last if $file = ($do_expand) ? dl_expandspec($try) : ((-f $try) && $try);
# no luck here, save dir for possible later dl_findfile search
push @dirs, $dir;
}
# last resort, let dl_findfile have a go in all known locations
$file = dl_findfile(map("-L$_",@dirs,@INC), $modfname) unless $file;
croak("Can't locate loadable object for module $module in \@INC (\@INC contains: @INC)")
unless $file; # wording similar to error from 'require'
my $bootname = "boot_$module";
$bootname =~ s/\W/_/g;
@dl_require_symbols = ($bootname);
# Execute optional '.bootstrap' perl script for this module.
# The .bs file can be used to configure @dl_resolve_using etc to
# match the needs of the individual module on this architecture.
# N.B. The .bs file does not following the naming convention used
# by mod2fname.
my $bs = "$dir/$modfname_orig";
$bs =~ s/(\.\w+)?(;\d*)?$/\.bs/; # look for .bs 'beside' the library
if (-s $bs) { # only read file if it's not empty
print STDERR "BS: $bs ($^O, $dlsrc)\n" if $dl_debug;
eval { local @INC = ('.'); do $bs; };
warn "$bs: $@\n" if $@;
}
my $boot_symbol_ref;
# Many dynamic extension loading problems will appear to come from
# this section of code: XYZ failed at line 123 of DynaLoader.pm.
# Often these errors are actually occurring in the initialisation
# C code of the extension XS file. Perl reports the error as being
# in this perl code simply because this was the last perl code
# it executed.
my $flags = $module->dl_load_flags;
my $libref = dl_load_file($file, $flags) or
croak("Can't load '$file' for module $module: ".dl_error());
push(@dl_librefs,$libref); # record loaded object
$boot_symbol_ref = dl_find_symbol($libref, $bootname) or
croak("Can't find '$bootname' symbol in $file\n");
push(@dl_modules, $module); # record loaded module
boot:
my $xs = dl_install_xsub("${module}::bootstrap", $boot_symbol_ref, $file);
# See comment block above
push(@dl_shared_objects, $file); # record files loaded
&$xs(@args);
}
sub dl_findfile {
# This function does not automatically consider the architecture
# or the perl library auto directories.
my (@args) = @_;
my (@dirs, $dir); # which directories to search
my (@found); # full paths to real files we have found
#my $dl_ext= 'so'; # $Config::Config{'dlext'} suffix for perl extensions
#my $dl_so = 'so'; # $Config::Config{'so'} suffix for shared libraries
print STDERR "dl_findfile(@args)\n" if $dl_debug;
# accumulate directories but process files as they appear
arg: foreach(@args) {
# Special fast case: full filepath requires no search
if (m:/: && -f $_) {
push(@found,$_);
last arg unless wantarray;
next;
}
# Deal with directories first:
# Using a -L prefix is the preferred option (faster and more robust)
if ( s{^-L}{} ) { push(@dirs, $_); next; }
# Otherwise we try to try to spot directories by a heuristic
# (this is a more complicated issue than it first appears)
if (m:/: && -d $_) { push(@dirs, $_); next; }
# Only files should get this far...
my(@names, $name); # what filenames to look for
if ( s{^-l}{} ) { # convert -lname to appropriate library name
push(@names, "lib$_.$dl_so", "lib$_.a");
} else { # Umm, a bare name. Try various alternatives:
# these should be ordered with the most likely first
push(@names,"$_.$dl_dlext") unless m/\.$dl_dlext$/o;
push(@names,"$_.$dl_so") unless m/\.$dl_so$/o;
push(@names,"lib$_.$dl_so") unless m:/:;
push(@names, $_);
}
my $dirsep = '/';
foreach $dir (@dirs, @dl_library_path) {
next unless -d $dir;
foreach $name (@names) {
my($file) = "$dir$dirsep$name";
print STDERR " checking in $dir for $name\n" if $dl_debug;
if ($do_expand && ($file = dl_expandspec($file))) {
push @found, $file;
next arg; # no need to look any further
}
elsif (-f $file) {
push(@found, $file);
next arg; # no need to look any further
}
}
}
}
if ($dl_debug) {
foreach(@dirs) {
print STDERR " dl_findfile ignored non-existent directory: $_\n" unless -d $_;
}
print STDERR "dl_findfile found: @found\n";
}
return $found[0] unless wantarray;
@found;
}
sub dl_expandspec {
my($spec) = @_;
# Optional function invoked if DynaLoader.pm sets $do_expand.
# Most systems do not require or use this function.
# Some systems may implement it in the dl_*.xs file in which case
# this Perl version should be excluded at build time.
# This function is designed to deal with systems which treat some
# 'filenames' in a special way. For example VMS 'Logical Names'
# (something like unix environment variables - but different).
# This function should recognise such names and expand them into
# full file paths.
# Must return undef if $spec is invalid or file does not exist.
my $file = $spec; # default output to input
return undef unless -f $file;
print STDERR "dl_expandspec($spec) => $file\n" if $dl_debug;
$file;
}
sub dl_find_symbol_anywhere
{
my $sym = shift;
my $libref;
foreach $libref (@dl_librefs) {
my $symref = dl_find_symbol($libref,$sym,1);
return $symref if $symref;
}
return undef;
}
__END__
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