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Edit File: DynaLoader.pm
# Generated from DynaLoader_pm.PL, this file is unique for every OS 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 { $VERSION = '1.45'; } 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)}; $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 = $_[0]; local *isa = *{"$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; $file = ($do_expand) ? dl_expandspec($file) : (-f $file && $file); #$file = _check_file($file); if ($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__