1 package Devel::SelfStubber;
11 # perl -e 'use Devel::SelfStubber;Devel::SelfStubber->stub(MODULE_NAME,LIB)'
12 # (LIB defaults to '.') e.g.
13 # perl -e 'use Devel::SelfStubber;Devel::SelfStubber->stub('Math::BigInt')'
14 # would print out stubs needed if you added a __DATA__ before the subs.
15 # Setting $Devel::SelfStubber::JUST_STUBS to 0 will print out the whole
16 # module with the stubs entered just before the __DATA__
19 my($self,$fullname,$pack,$lines, $prototype) = @_;
20 push(@DATA,@{$lines});
21 if($fullname){push(@STUBS,"sub $fullname $prototype;\n")}; # stubs
25 sub _package_defined {
31 my($self,$module,$lib) = @_;
32 my($line,$end_data,$fh,$mod_file,$found_selfloader);
33 $lib ||= File::Spec->curdir();
34 ($mod_file = $module) =~ s,::,/,g;
35 $mod_file =~ tr|/|:| if $^O eq 'MacOS';
37 $mod_file = File::Spec->catfile($lib, "$mod_file.pm");
38 $fh = "${module}::DATA";
39 my (@BEFORE_DATA, @AFTER_DATA, @AFTER_END);
42 open($fh,$mod_file) || die "Unable to open $mod_file";
44 while(defined ($line = <$fh>) and $line !~ m/^__DATA__/) {
45 push(@BEFORE_DATA,$line);
46 $line =~ /use\s+SelfLoader/ && $found_selfloader++;
48 (defined ($line) && $line =~ m/^__DATA__/)
49 || die "$mod_file doesn't contain a __DATA__ token";
51 print 'die "\'use SelfLoader;\' statement NOT FOUND!!\n"',"\n";
53 $self->_load_stubs($module);
55 $self->_load_stubs($module, \@AFTER_END);
59 while(defined($line = <$fh>)) {
60 push(@AFTER_DATA,$line);
64 unless ($JUST_STUBS) {
68 unless ($JUST_STUBS) {
69 print "1;\n__DATA__\n",@DATA;
70 if($end_data) { print "__END__ DATA\n",@AFTER_DATA; }
71 if(@AFTER_END) { print "__END__\n",@AFTER_END; }
80 Devel::SelfStubber - generate stubs for a SelfLoading module
84 To generate just the stubs:
86 use Devel::SelfStubber;
87 Devel::SelfStubber->stub('MODULENAME','MY_LIB_DIR');
89 or to generate the whole module with stubs inserted correctly
91 use Devel::SelfStubber;
92 $Devel::SelfStubber::JUST_STUBS=0;
93 Devel::SelfStubber->stub('MODULENAME','MY_LIB_DIR');
95 MODULENAME is the Perl module name, e.g. Devel::SelfStubber,
96 NOT 'Devel/SelfStubber' or 'Devel/SelfStubber.pm'.
98 MY_LIB_DIR defaults to '.' if not present.
102 Devel::SelfStubber prints the stubs you need to put in the module
103 before the __DATA__ token (or you can get it to print the entire
104 module with stubs correctly placed). The stubs ensure that if
105 a method is called, it will get loaded. They are needed specifically
106 for inherited autoloaded methods.
108 This is best explained using the following example:
110 Assume four classes, A,B,C & D.
112 A is the root class, B is a subclass of A, C is a subclass of B,
113 and D is another subclass of A.
121 If D calls an autoloaded method 'foo' which is defined in class A,
122 then the method is loaded into class A, then executed. If C then
123 calls method 'foo', and that method was reimplemented in class
124 B, but set to be autoloaded, then the lookup mechanism never gets to
125 the AUTOLOAD mechanism in B because it first finds the method
126 already loaded in A, and so erroneously uses that. If the method
127 foo had been stubbed in B, then the lookup mechanism would have
128 found the stub, and correctly loaded and used the sub from B.
130 So, for classes and subclasses to have inheritance correctly
131 work with autoloading, you need to ensure stubs are loaded.
133 The SelfLoader can load stubs automatically at module initialization
134 with the statement 'SelfLoader-E<gt>load_stubs()';, but you may wish to
135 avoid having the stub loading overhead associated with your
136 initialization (though note that the SelfLoader::load_stubs method
137 will be called sooner or later - at latest when the first sub
138 is being autoloaded). In this case, you can put the sub stubs
139 before the __DATA__ token. This can be done manually, but this
140 module allows automatic generation of the stubs.
142 By default it just prints the stubs, but you can set the
143 global $Devel::SelfStubber::JUST_STUBS to 0 and it will
144 print out the entire module with the stubs positioned correctly.
146 At the very least, this is useful to see what the SelfLoader
147 thinks are stubs - in order to ensure future versions of the
148 SelfStubber remain in step with the SelfLoader, the
149 SelfStubber actually uses the SelfLoader to determine which