1 package ExtUtils::MakeMaker::FAQ;
3 (our $VERSION) = sprintf "%03d", q$Revision: 1.7 $ =~ /Revision:\s+(\S+)/;
10 ExtUtils::MakeMaker::FAQ - Frequently Asked Questions About MakeMaker
14 FAQs, tricks and tips for C<ExtUtils::MakeMaker>.
16 =head2 Philosophy and History
20 =item Why not just use <insert other build config tool here>?
22 Why did MakeMaker reinvent the build configuration wheel? Why not
23 just use autoconf or automake or ppm or Ant or ...
25 There are many reasons, but the major one is cross-platform
28 Perl is one of the most ported pieces of software ever. It works on
29 operating systems I've never even heard of (see perlport for details).
30 It needs a build tool that can work on all those platforms and with
31 any wacky C compilers they might have.
33 No such build tool existed at the time and I only know of one now
37 =item What's Module::Build and how does it relate to MakeMaker?
39 Module::Build is a project by Ken Williams to supplant MakeMaker.
40 Its primary advantages are:
44 =item * pure perl. no make, no shell commands
46 =item * easier to customize
48 =item * cleaner internals
54 Module::Build is the official heir apparent to MakeMaker and we
55 encourage people to work on M::B rather than spending time improving
66 How do I keep my $VERSION up to date without resetting it manually?
68 Often you want to manually set the $VERSION in the main module
69 distribution because this is the version that everybody sees on CPAN
70 and maybe you want to customize it a bit. But for all the other
71 modules in your dist, $VERSION is really just bookkeeping and all that's
72 important is it goes up every time the module is changed. Doing this
73 by hand is a pain and you often forget.
75 Simplest way to do it automatically is to use your version control
76 system's revision number (you are using version control, right?).
78 In CVS and RCS you use $Z<>Revision$ writing it like so:
80 $VERSION = sprintf "%d.%03d", q$Revision$ =~ /(\d+)/g;
82 On your next check in, $Z<>Revision$ will magically be expanded to contain
83 the current revision #.
85 $VERSION = sprintf "%d.%03d", q$Revision: 1.7 $ =~ /(\d+)/g;
87 Every time the file is checked in the $Z<>Revision$ will be updated,
88 updating your $VERSION.
90 In CVS version 1.9 is followed by 1.10. Since CPAN compares version
91 numbers numerically we use a sprintf() to convert 1.9 to 1.009 and
92 1.10 to 1.010 which compare properly.
94 If branches are involved (ie. $Z<>Revision: 1.5.3.4) its a little more
97 # must be all on one line or MakeMaker will get confused.
98 $VERSION = do { my @r = (q$Revision$ =~ /\d+/g); sprintf "%d."."%03d" x $#r, @r };
102 What's this F<META.yml> thing and how did it get in my F<MANIFEST>?!
104 F<META.yml> is a module meta-data file pioneered by Module::Build and
105 automatically generated as part of the 'distdir' target (and thus
106 'dist'). See L<ExtUtils::MakeMaker/"Module Meta-Data">.
108 To shut off its generation, pass the C<NO_META> flag to C<WriteMakefile()>.
118 How to I prevent "object version X.XX does not match bootstrap parameter Y.YY"
121 XS code is very sensitive to the module version number and will
122 complain if the version number in your Perl module doesn't match. If
123 you change your module's version # without reruning Makefile.PL the old
124 version number will remain in the Makefile causing the XS code to be built
125 with the wrong number.
127 To avoid this, you can force the Makefile to be rebuilt whenever you
128 change the module containing the version number by adding this to your
129 WriteMakefile() arguments.
131 depend => { '$(FIRST_MAKEFILE)' => '$(VERSION_FROM)' }
136 How do I make two or more XS files coexist in the same directory?
138 Sometimes you need to have two and more XS files in the same package.
139 One way to go is to put them into separate directories, but sometimes
140 this is not the most suitable solution. The following technique allows
141 you to put two (and more) XS files in the same directory.
143 Let's assume that we have a package C<Cool::Foo>, which includes
144 C<Cool::Foo> and C<Cool::Bar> modules each having a separate XS
145 file. First we use the following I<Makefile.PL>:
147 use ExtUtils::MakeMaker;
151 VERSION_FROM => 'Foo.pm',
152 OBJECT => q/$(O_FILES)/,
153 # ... other attrs ...
156 Notice the C<OBJECT> attribute. MakeMaker generates the following
157 variables in I<Makefile>:
159 # Handy lists of source code files:
167 Therefore we can use the C<O_FILES> variable to tell MakeMaker to use
168 these objects into the shared library.
170 That's pretty much it. Now write I<Foo.pm> and I<Foo.xs>, I<Bar.pm>
171 and I<Bar.xs>, where I<Foo.pm> bootstraps the shared library and
172 I<Bar.pm> simply loading I<Foo.pm>.
174 The only issue left is to how to bootstrap I<Bar.xs>. This is done
177 MODULE = Cool::Foo PACKAGE = Cool::Foo
180 # boot the second XS file
181 boot_Cool__Bar(aTHX_ cv);
183 If you have more than two files, this is the place where you should
184 boot extra XS files from.
186 The following four files sum up all the details discussed so far.
194 our @ISA = qw(DynaLoader);
195 our $VERSION = '0.01';
196 bootstrap Cool::Foo $VERSION;
204 use Cool::Foo; # bootstraps Bar.xs
214 MODULE = Cool::Foo PACKAGE = Cool::Foo
217 # boot the second XS file
218 boot_Cool__Bar(aTHX_ cv);
220 MODULE = Cool::Foo PACKAGE = Cool::Foo PREFIX = cool_foo_
223 cool_foo_perl_rules()
226 fprintf(stderr, "Cool::Foo says: Perl Rules\n");
234 MODULE = Cool::Bar PACKAGE = Cool::Bar PREFIX = cool_bar_
237 cool_bar_perl_rules()
240 fprintf(stderr, "Cool::Bar says: Perl Rules\n");
242 And of course a very basic test:
247 BEGIN { plan tests => 1 };
250 Cool::Foo::perl_rules();
251 Cool::Bar::perl_rules();
254 This tip has been brought to you by Nick Ing-Simmons and Stas Bekman.
260 If you have a question you'd like to see added to the FAQ (whether or
261 not you have the answer) please send it to makemaker@perl.org.
265 The denizens of makemaker@perl.org.
269 L<ExtUtils::MakeMaker>