1 package ExtUtils::MakeMaker::FAQ;
11 ExtUtils::MakeMaker::FAQ - Frequently Asked Questions About MakeMaker
15 FAQs, tricks and tips for C<ExtUtils::MakeMaker>.
18 =head2 Module Installation
22 =item How do I keep from installing man pages?
24 Recent versions of MakeMaker will only install man pages on Unix like
27 For an individual module:
29 perl Makefile.PL INSTALLMAN1DIR=none INSTALLMAN3DIR=none
31 If you want to suppress man page installation for all modules you have
32 to reconfigure Perl and tell it 'none' when it asks where to install
36 =item How do I use a module without installing it?
38 Two ways. One is to build the module normally...
43 ...and then set the PERL5LIB environment variable to point at the
44 blib/lib and blib/arch directories.
46 The other is to install the module in a temporary location.
48 perl Makefile.PL PREFIX=~/tmp LIB=~/tmp/lib/perl
50 And then set PERL5LIB to F<~/tmp/lib/perl>. This works well when you have
51 multiple modules to work with. It also ensures that the module goes
52 through its full installation process which may modify it.
57 =head2 Philosophy and History
61 =item Why not just use <insert other build config tool here>?
63 Why did MakeMaker reinvent the build configuration wheel? Why not
64 just use autoconf or automake or ppm or Ant or ...
66 There are many reasons, but the major one is cross-platform
69 Perl is one of the most ported pieces of software ever. It works on
70 operating systems I've never even heard of (see perlport for details).
71 It needs a build tool that can work on all those platforms and with
72 any wacky C compilers and linkers they might have.
74 No such build tool exists. Even make itself has wildly different
75 dialects. So we have to build our own.
78 =item What is Module::Build and how does it relate to MakeMaker?
80 Module::Build is a project by Ken Williams to supplant MakeMaker.
81 Its primary advantages are:
85 =item * pure perl. no make, no shell commands
87 =item * easier to customize
89 =item * cleaner internals
95 Module::Build is the official heir apparent to MakeMaker and we
96 encourage people to work on M::B rather than spending time adding features
102 =head2 Module Writing
106 =item How do I keep my $VERSION up to date without resetting it manually?
108 Often you want to manually set the $VERSION in the main module
109 distribution because this is the version that everybody sees on CPAN
110 and maybe you want to customize it a bit. But for all the other
111 modules in your dist, $VERSION is really just bookkeeping and all that's
112 important is it goes up every time the module is changed. Doing this
113 by hand is a pain and you often forget.
115 Simplest way to do it automatically is to use your version control
116 system's revision number (you are using version control, right?).
118 In CVS, RCS and SVN you use $Revision$ (see the documentation of your
119 version control system for details). Every time the file is checked
120 in the $Revision$ will be updated, updating your $VERSION.
122 SVN uses a simple integer for $Revision$ so you can adapt it for your
125 $VERSION = (q$Revision$) =~ /(\d+)/g;
127 In CVS and RCS version 1.9 is followed by 1.10. Since CPAN compares
128 version numbers numerically we use a sprintf() to convert 1.9 to 1.009
129 and 1.10 to 1.010 which compare properly.
131 $VERSION = sprintf "%d.%03d", q$Revision$ =~ /(\d+)\.(\d+)/g;
133 If branches are involved (ie. $Revision: 1.5.3.4$) its a little more
136 # must be all on one line or MakeMaker will get confused.
137 $VERSION = do { my @r = (q$Revision$ =~ /\d+/g); sprintf "%d."."%03d" x $#r, @r };
139 In SVN, $Revision$ should be the same for every file in the project so
140 they would all have the same $VERSION. CVS and RCS have a different
141 $Revision$ per file so each file will have a differnt $VERSION.
142 Distributed version control systems, such as SVK, may have a different
143 $Revision$ based on who checks out the file leading to a different $VERSION
144 on each machine! Finally, some distributed version control systems, such
145 as darcs, have no concept of revision number at all.
148 =item What's this F<META.yml> thing and how did it get in my F<MANIFEST>?!
150 F<META.yml> is a module meta-data file pioneered by Module::Build and
151 automatically generated as part of the 'distdir' target (and thus
152 'dist'). See L<ExtUtils::MakeMaker/"Module Meta-Data">.
154 To shut off its generation, pass the C<NO_META> flag to C<WriteMakefile()>.
162 =item How to I prevent "object version X.XX does not match bootstrap parameter Y.YY" errors?
164 XS code is very sensitive to the module version number and will
165 complain if the version number in your Perl module doesn't match. If
166 you change your module's version # without rerunning Makefile.PL the old
167 version number will remain in the Makefile causing the XS code to be built
168 with the wrong number.
170 To avoid this, you can force the Makefile to be rebuilt whenever you
171 change the module containing the version number by adding this to your
172 WriteMakefile() arguments.
174 depend => { '$(FIRST_MAKEFILE)' => '$(VERSION_FROM)' }
177 =item How do I make two or more XS files coexist in the same directory?
179 Sometimes you need to have two and more XS files in the same package.
180 One way to go is to put them into separate directories, but sometimes
181 this is not the most suitable solution. The following technique allows
182 you to put two (and more) XS files in the same directory.
184 Let's assume that we have a package C<Cool::Foo>, which includes
185 C<Cool::Foo> and C<Cool::Bar> modules each having a separate XS
186 file. First we use the following I<Makefile.PL>:
188 use ExtUtils::MakeMaker;
192 VERSION_FROM => 'Foo.pm',
193 OBJECT => q/$(O_FILES)/,
194 # ... other attrs ...
197 Notice the C<OBJECT> attribute. MakeMaker generates the following
198 variables in I<Makefile>:
200 # Handy lists of source code files:
208 Therefore we can use the C<O_FILES> variable to tell MakeMaker to use
209 these objects into the shared library.
211 That's pretty much it. Now write I<Foo.pm> and I<Foo.xs>, I<Bar.pm>
212 and I<Bar.xs>, where I<Foo.pm> bootstraps the shared library and
213 I<Bar.pm> simply loading I<Foo.pm>.
215 The only issue left is to how to bootstrap I<Bar.xs>. This is done
218 MODULE = Cool::Foo PACKAGE = Cool::Foo
221 # boot the second XS file
222 boot_Cool__Bar(aTHX_ cv);
224 If you have more than two files, this is the place where you should
225 boot extra XS files from.
227 The following four files sum up all the details discussed so far.
235 our @ISA = qw(DynaLoader);
236 our $VERSION = '0.01';
237 bootstrap Cool::Foo $VERSION;
245 use Cool::Foo; # bootstraps Bar.xs
255 MODULE = Cool::Foo PACKAGE = Cool::Foo
258 # boot the second XS file
259 boot_Cool__Bar(aTHX_ cv);
261 MODULE = Cool::Foo PACKAGE = Cool::Foo PREFIX = cool_foo_
264 cool_foo_perl_rules()
267 fprintf(stderr, "Cool::Foo says: Perl Rules\n");
275 MODULE = Cool::Bar PACKAGE = Cool::Bar PREFIX = cool_bar_
278 cool_bar_perl_rules()
281 fprintf(stderr, "Cool::Bar says: Perl Rules\n");
283 And of course a very basic test:
288 BEGIN { plan tests => 1 };
291 Cool::Foo::perl_rules();
292 Cool::Bar::perl_rules();
295 This tip has been brought to you by Nick Ing-Simmons and Stas Bekman.
301 If you have a question you'd like to see added to the FAQ (whether or
302 not you have the answer) please send it to makemaker@perl.org.
306 The denizens of makemaker@perl.org.
310 L<ExtUtils::MakeMaker>