1package ExtUtils::MakeMaker::FAQ; 2 3our $VERSION = '7.70'; 4$VERSION =~ tr/_//d; 5 61; 7__END__ 8 9=head1 NAME 10 11ExtUtils::MakeMaker::FAQ - Frequently Asked Questions About MakeMaker 12 13=head1 DESCRIPTION 14 15FAQs, tricks and tips for L<ExtUtils::MakeMaker>. 16 17 18=head2 Module Installation 19 20=over 4 21 22=item How do I install a module into my home directory? 23 24If you're not the Perl administrator you probably don't have 25permission to install a module to its default location. Ways of handling 26this with a B<lot> less manual effort on your part are L<perlbrew> 27and L<local::lib>. 28 29Otherwise, you can install it for your own use into your home directory 30like so: 31 32 # Non-unix folks, replace ~ with /path/to/your/home/dir 33 perl Makefile.PL INSTALL_BASE=~ 34 35This will put modules into F<~/lib/perl5>, man pages into F<~/man> and 36programs into F<~/bin>. 37 38To ensure your Perl programs can see these newly installed modules, 39set your C<PERL5LIB> environment variable to F<~/lib/perl5> or tell 40each of your programs to look in that directory with the following: 41 42 use lib "$ENV{HOME}/lib/perl5"; 43 44or if $ENV{HOME} isn't set and you don't want to set it for some 45reason, do it the long way. 46 47 use lib "/path/to/your/home/dir/lib/perl5"; 48 49=item How do I get MakeMaker and Module::Build to install to the same place? 50 51Module::Build, as of 0.28, supports two ways to install to the same 52location as MakeMaker. 53 54We highly recommend the install_base method, its the simplest and most 55closely approximates the expected behavior of an installation prefix. 56 571) Use INSTALL_BASE / C<--install_base> 58 59MakeMaker (as of 6.31) and Module::Build (as of 0.28) both can install 60to the same locations using the "install_base" concept. See 61L<ExtUtils::MakeMaker/INSTALL_BASE> for details. To get MM and MB to 62install to the same location simply set INSTALL_BASE in MM and 63C<--install_base> in MB to the same location. 64 65 perl Makefile.PL INSTALL_BASE=/whatever 66 perl Build.PL --install_base /whatever 67 68This works most like other language's behavior when you specify a 69prefix. We recommend this method. 70 712) Use PREFIX / C<--prefix> 72 73Module::Build 0.28 added support for C<--prefix> which works like 74MakeMaker's PREFIX. 75 76 perl Makefile.PL PREFIX=/whatever 77 perl Build.PL --prefix /whatever 78 79We highly discourage this method. It should only be used if you know 80what you're doing and specifically need the PREFIX behavior. The 81PREFIX algorithm is complicated and focused on matching the system 82installation. 83 84=item How do I keep from installing man pages? 85 86Recent versions of MakeMaker will only install man pages on Unix-like 87operating systems by default. To generate manpages on non-Unix operating 88systems, make the "manifypods" target. 89 90For an individual module: 91 92 perl Makefile.PL INSTALLMAN1DIR=none INSTALLMAN3DIR=none 93 94If you want to suppress man page installation for all modules you have 95to reconfigure Perl and tell it 'none' when it asks where to install 96man pages. 97 98 99=item How do I use a module without installing it? 100 101Two ways. One is to build the module normally... 102 103 perl Makefile.PL 104 make 105 make test 106 107...and then use L<blib> to point Perl at the built but uninstalled module: 108 109 perl -Mblib script.pl 110 perl -Mblib -e '...' 111 112The other is to install the module in a temporary location. 113 114 perl Makefile.PL INSTALL_BASE=~/tmp 115 make 116 make test 117 make install 118 119And then set PERL5LIB to F<~/tmp/lib/perl5>. This works well when you 120have multiple modules to work with. It also ensures that the module 121goes through its full installation process which may modify it. 122Again, L<local::lib> may assist you here. 123 124=item How can I organize tests into subdirectories and have them run? 125 126Let's take the following test directory structure: 127 128 t/foo/sometest.t 129 t/bar/othertest.t 130 t/bar/baz/anothertest.t 131 132Now, inside of the C<WriteMakefile()> function in your F<Makefile.PL>, specify 133where your tests are located with the C<test> directive: 134 135 test => {TESTS => 't/*.t t/*/*.t t/*/*/*.t'} 136 137The first entry in the string will run all tests in the top-level F<t/> 138directory. The second will run all test files located in any subdirectory under 139F<t/>. The third, runs all test files within any subdirectory within any other 140subdirectory located under F<t/>. 141 142Note that you do not have to use wildcards. You can specify explicitly which 143subdirectories to run tests in: 144 145 test => {TESTS => 't/*.t t/foo/*.t t/bar/baz/*.t'} 146 147=item PREFIX vs INSTALL_BASE from Module::Build::Cookbook 148 149The behavior of PREFIX is complicated and depends closely on how your 150Perl is configured. The resulting installation locations will vary 151from machine to machine and even different installations of Perl on the 152same machine. Because of this, its difficult to document where prefix 153will place your modules. 154 155In contrast, INSTALL_BASE has predictable, easy to explain installation 156locations. Now that Module::Build and MakeMaker both have INSTALL_BASE 157there is little reason to use PREFIX other than to preserve your existing 158installation locations. If you are starting a fresh Perl installation we 159encourage you to use INSTALL_BASE. If you have an existing installation 160installed via PREFIX, consider moving it to an installation structure 161matching INSTALL_BASE and using that instead. 162 163=item Generating *.pm files with substitutions eg of $VERSION 164 165If you want to configure your module files for local conditions, or to 166automatically insert a version number, you can use EUMM's C<PL_FILES> 167capability, where it will automatically run each F<*.PL> it finds to 168generate its basename. For instance: 169 170 # Makefile.PL: 171 require 'common.pl'; 172 my $version = get_version(); 173 my @pms = qw(Foo.pm); 174 WriteMakefile( 175 NAME => 'Foo', 176 VERSION => $version, 177 PM => { map { ($_ => "\$(INST_LIB)/$_") } @pms }, 178 clean => { FILES => join ' ', @pms }, 179 ); 180 181 # common.pl: 182 sub get_version { '0.04' } 183 sub process { my $v = get_version(); s/__VERSION__/$v/g; } 184 1; 185 186 # Foo.pm.PL: 187 require 'common.pl'; 188 $_ = join '', <DATA>; 189 process(); 190 my $file = shift; 191 open my $fh, '>', $file or die "$file: $!"; 192 print $fh $_; 193 __DATA__ 194 package Foo; 195 our $VERSION = '__VERSION__'; 196 1; 197 198You may notice that C<PL_FILES> is not specified above, since the default 199of mapping each .PL file to its basename works well. 200 201If the generated module were architecture-specific, you could replace 202C<$(INST_LIB)> above with C<$(INST_ARCHLIB)>, although if you locate 203modules under F<lib>, that would involve ensuring any C<lib/> in front 204of the module location were removed. 205 206=back 207 208=head2 Common errors and problems 209 210=over 4 211 212=item "No rule to make target `/usr/lib/perl5/CORE/config.h', needed by `Makefile'" 213 214Just what it says, you're missing that file. MakeMaker uses it to 215determine if perl has been rebuilt since the Makefile was made. It's 216a bit of a bug that it halts installation. 217 218Some operating systems don't ship the CORE directory with their base 219perl install. To solve the problem, you likely need to install a perl 220development package such as perl-devel (CentOS, Fedora and other 221Redhat systems) or perl (Ubuntu and other Debian systems). 222 223=back 224 225=head2 Philosophy and History 226 227=over 4 228 229=item Why not just use <insert other build config tool here>? 230 231Why did MakeMaker reinvent the build configuration wheel? Why not 232just use autoconf or automake or ppm or Ant or ... 233 234There are many reasons, but the major one is cross-platform 235compatibility. 236 237Perl is one of the most ported pieces of software ever. It works on 238operating systems I've never even heard of (see perlport for details). 239It needs a build tool that can work on all those platforms and with 240any wacky C compilers and linkers they might have. 241 242No such build tool exists. Even make itself has wildly different 243dialects. So we have to build our own. 244 245 246=item What is Module::Build and how does it relate to MakeMaker? 247 248Module::Build is a project by Ken Williams to supplant MakeMaker. 249Its primary advantages are: 250 251=over 8 252 253=item * pure perl. no make, no shell commands 254 255=item * easier to customize 256 257=item * cleaner internals 258 259=item * less cruft 260 261=back 262 263Module::Build was long the official heir apparent to MakeMaker. The 264rate of both its development and adoption has slowed in recent years, 265though, and it is unclear what the future holds for it. That said, 266Module::Build set the stage for I<something> to become the heir to 267MakeMaker. MakeMaker's maintainers have long said that it is a dead 268end and should be kept functioning, while being cautious about extending 269with new features. 270 271=back 272 273=head2 Module Writing 274 275=over 4 276 277=item How do I keep my $VERSION up to date without resetting it manually? 278 279Often you want to manually set the $VERSION in the main module 280distribution because this is the version that everybody sees on CPAN 281and maybe you want to customize it a bit. But for all the other 282modules in your dist, $VERSION is really just bookkeeping and all that's 283important is it goes up every time the module is changed. Doing this 284by hand is a pain and you often forget. 285 286Probably the easiest way to do this is using F<perl-reversion> in 287L<Perl::Version>: 288 289 perl-reversion -bump 290 291If your version control system supports revision numbers (git doesn't 292easily), the simplest way to do it automatically is to use its revision 293number (you are using version control, right?). 294 295In CVS, RCS and SVN you use $Revision$ (see the documentation of your 296version control system for details). Every time the file is checked 297in the $Revision$ will be updated, updating your $VERSION. 298 299SVN uses a simple integer for $Revision$ so you can adapt it for your 300$VERSION like so: 301 302 ($VERSION) = q$Revision$ =~ /(\d+)/; 303 304In CVS and RCS version 1.9 is followed by 1.10. Since CPAN compares 305version numbers numerically we use a sprintf() to convert 1.9 to 1.009 306and 1.10 to 1.010 which compare properly. 307 308 $VERSION = sprintf "%d.%03d", q$Revision$ =~ /(\d+)\.(\d+)/g; 309 310If branches are involved (ie. $Revision: 1.5.3.4$) it's a little more 311complicated. 312 313 # must be all on one line or MakeMaker will get confused. 314 $VERSION = do { my @r = (q$Revision$ =~ /\d+/g); sprintf "%d."."%03d" x $#r, @r }; 315 316In SVN, $Revision$ should be the same for every file in the project so 317they would all have the same $VERSION. CVS and RCS have a different 318$Revision$ per file so each file will have a different $VERSION. 319Distributed version control systems, such as SVK, may have a different 320$Revision$ based on who checks out the file, leading to a different $VERSION 321on each machine! Finally, some distributed version control systems, such 322as darcs, have no concept of revision number at all. 323 324 325=item What's this F<META.yml> thing and how did it get in my F<MANIFEST>?! 326 327F<META.yml> is a module meta-data file pioneered by Module::Build and 328automatically generated as part of the 'distdir' target (and thus 329'dist'). See L<ExtUtils::MakeMaker/"Module Meta-Data">. 330 331To shut off its generation, pass the C<NO_META> flag to C<WriteMakefile()>. 332 333 334=item How do I delete everything not in my F<MANIFEST>? 335 336Some folks are surprised that C<make distclean> does not delete 337everything not listed in their MANIFEST (thus making a clean 338distribution) but only tells them what they need to delete. This is 339done because it is considered too dangerous. While developing your 340module you might write a new file, not add it to the MANIFEST, then 341run a C<distclean> and be sad because your new work was deleted. 342 343If you really want to do this, you can use 344C<ExtUtils::Manifest::manifind()> to read the MANIFEST and File::Find 345to delete the files. But you have to be careful. Here's a script to 346do that. Use at your own risk. Have fun blowing holes in your foot. 347 348 #!/usr/bin/perl -w 349 350 use strict; 351 352 use File::Spec; 353 use File::Find; 354 use ExtUtils::Manifest qw(maniread); 355 356 my %manifest = map {( $_ => 1 )} 357 grep { File::Spec->canonpath($_) } 358 keys %{ maniread() }; 359 360 if( !keys %manifest ) { 361 print "No files found in MANIFEST. Stopping.\n"; 362 exit; 363 } 364 365 find({ 366 wanted => sub { 367 my $path = File::Spec->canonpath($_); 368 369 return unless -f $path; 370 return if exists $manifest{ $path }; 371 372 print "unlink $path\n"; 373 unlink $path; 374 }, 375 no_chdir => 1 376 }, 377 "." 378 ); 379 380 381=item Which tar should I use on Windows? 382 383We recommend ptar from Archive::Tar not older than 1.66 with '-C' option. 384 385=item Which zip should I use on Windows for '[ndg]make zipdist'? 386 387We recommend InfoZIP: L<http://www.info-zip.org/Zip.html> 388 389 390=back 391 392=head2 XS 393 394=over 4 395 396=item How do I prevent "object version X.XX does not match bootstrap parameter Y.YY" errors? 397 398XS code is very sensitive to the module version number and will 399complain if the version number in your Perl module doesn't match. If 400you change your module's version # without rerunning Makefile.PL the old 401version number will remain in the Makefile, causing the XS code to be built 402with the wrong number. 403 404To avoid this, you can force the Makefile to be rebuilt whenever you 405change the module containing the version number by adding this to your 406WriteMakefile() arguments. 407 408 depend => { '$(FIRST_MAKEFILE)' => '$(VERSION_FROM)' } 409 410 411=item How do I make two or more XS files coexist in the same directory? 412 413Sometimes you need to have two and more XS files in the same package. 414There are three ways: C<XSMULTI>, separate directories, and bootstrapping 415one XS from another. 416 417=over 8 418 419=item XSMULTI 420 421Structure your modules so they are all located under F<lib>, such that 422C<Foo::Bar> is in F<lib/Foo/Bar.pm> and F<lib/Foo/Bar.xs>, etc. Have your 423top-level C<WriteMakefile> set the variable C<XSMULTI> to a true value. 424 425Er, that's it. 426 427=item Separate directories 428 429Put each XS files into separate directories, each with their own 430F<Makefile.PL>. Make sure each of those F<Makefile.PL>s has the correct 431C<CFLAGS>, C<INC>, C<LIBS> etc. You will need to make sure the top-level 432F<Makefile.PL> refers to each of these using C<DIR>. 433 434=item Bootstrapping 435 436Let's assume that we have a package C<Cool::Foo>, which includes 437C<Cool::Foo> and C<Cool::Bar> modules each having a separate XS 438file. First we use the following I<Makefile.PL>: 439 440 use ExtUtils::MakeMaker; 441 442 WriteMakefile( 443 NAME => 'Cool::Foo', 444 VERSION_FROM => 'Foo.pm', 445 OBJECT => q/$(O_FILES)/, 446 # ... other attrs ... 447 ); 448 449Notice the C<OBJECT> attribute. MakeMaker generates the following 450variables in I<Makefile>: 451 452 # Handy lists of source code files: 453 XS_FILES= Bar.xs \ 454 Foo.xs 455 C_FILES = Bar.c \ 456 Foo.c 457 O_FILES = Bar.o \ 458 Foo.o 459 460Therefore we can use the C<O_FILES> variable to tell MakeMaker to use 461these objects into the shared library. 462 463That's pretty much it. Now write I<Foo.pm> and I<Foo.xs>, I<Bar.pm> 464and I<Bar.xs>, where I<Foo.pm> bootstraps the shared library and 465I<Bar.pm> simply loading I<Foo.pm>. 466 467The only issue left is to how to bootstrap I<Bar.xs>. This is done 468from I<Foo.xs>: 469 470 MODULE = Cool::Foo PACKAGE = Cool::Foo 471 472 BOOT: 473 # boot the second XS file 474 boot_Cool__Bar(aTHX_ cv); 475 476If you have more than two files, this is the place where you should 477boot extra XS files from. 478 479The following four files sum up all the details discussed so far. 480 481 Foo.pm: 482 ------- 483 package Cool::Foo; 484 485 require DynaLoader; 486 487 our @ISA = qw(DynaLoader); 488 our $VERSION = '0.01'; 489 bootstrap Cool::Foo $VERSION; 490 491 1; 492 493 Bar.pm: 494 ------- 495 package Cool::Bar; 496 497 use Cool::Foo; # bootstraps Bar.xs 498 499 1; 500 501 Foo.xs: 502 ------- 503 #include "EXTERN.h" 504 #include "perl.h" 505 #include "XSUB.h" 506 507 MODULE = Cool::Foo PACKAGE = Cool::Foo 508 509 BOOT: 510 # boot the second XS file 511 boot_Cool__Bar(aTHX_ cv); 512 513 MODULE = Cool::Foo PACKAGE = Cool::Foo PREFIX = cool_foo_ 514 515 void 516 cool_foo_perl_rules() 517 518 CODE: 519 fprintf(stderr, "Cool::Foo says: Perl Rules\n"); 520 521 Bar.xs: 522 ------- 523 #include "EXTERN.h" 524 #include "perl.h" 525 #include "XSUB.h" 526 527 MODULE = Cool::Bar PACKAGE = Cool::Bar PREFIX = cool_bar_ 528 529 void 530 cool_bar_perl_rules() 531 532 CODE: 533 fprintf(stderr, "Cool::Bar says: Perl Rules\n"); 534 535And of course a very basic test: 536 537 t/cool.t: 538 -------- 539 use Test::More tests => 1; 540 use Cool::Foo; 541 use Cool::Bar; 542 Cool::Foo::perl_rules(); 543 Cool::Bar::perl_rules(); 544 ok 1; 545 546This tip has been brought to you by Nick Ing-Simmons and Stas Bekman. 547 548An alternative way to achieve this can be seen in L<Gtk2::CodeGen> 549and L<Glib::CodeGen>. 550 551=back 552 553=back 554 555=head1 DESIGN 556 557=head2 MakeMaker object hierarchy (simplified) 558 559What most people need to know (superclasses on top.) 560 561 ExtUtils::MM_Any 562 | 563 ExtUtils::MM_Unix 564 | 565 ExtUtils::MM_{Current OS} 566 | 567 ExtUtils::MakeMaker 568 | 569 MY 570 571The object actually used is of the class L<MY|ExtUtils::MY> which allows you to 572override bits of MakeMaker inside your Makefile.PL by declaring 573MY::foo() methods. 574 575=head2 MakeMaker object hierarchy (real) 576 577Here's how it really works: 578 579 ExtUtils::MM_Any 580 | 581 ExtUtils::MM_Unix 582 | 583 ExtUtils::Liblist::Kid ExtUtils::MM_{Current OS} (if necessary) 584 | | 585 ExtUtils::Liblist ExtUtils::MakeMaker | 586 | | | 587 | | |----------------------- 588 ExtUtils::MM 589 | | 590 ExtUtils::MY MM (created by ExtUtils::MM) 591 | | 592 MY (created by ExtUtils::MY) | 593 . | 594 (mixin) | 595 . | 596 PACK### (created each call to ExtUtils::MakeMaker->new) 597 598NOTE: Yes, this is a mess. See 599L<http://archive.develooper.com/makemaker@perl.org/msg00134.html> 600for some history. 601 602NOTE: When L<ExtUtils::MM> is loaded it chooses a superclass for MM from 603amongst the ExtUtils::MM_* modules based on the current operating 604system. 605 606NOTE: ExtUtils::MM_{Current OS} represents one of the ExtUtils::MM_* 607modules except L<ExtUtils::MM_Any> chosen based on your operating system. 608 609NOTE: The main object used by MakeMaker is a PACK### object, *not* 610L<ExtUtils::MakeMaker>. It is, effectively, a subclass of L<MY|ExtUtils::MY>, 611L<ExtUtils::MakeMaker>, L<ExtUtils::Liblist> and ExtUtils::MM_{Current OS} 612 613NOTE: The methods in L<MY|ExtUtils::MY> are simply copied into PACK### rather 614than MY being a superclass of PACK###. I don't remember the rationale. 615 616NOTE: L<ExtUtils::Liblist> should be removed from the inheritance hiearchy 617and simply be called as functions. 618 619NOTE: Modules like L<File::Spec> and L<Exporter> have been omitted for clarity. 620 621 622=head2 The MM_* hierarchy 623 624 MM_Win95 MM_NW5 625 \ / 626 MM_BeOS MM_Cygwin MM_OS2 MM_VMS MM_Win32 MM_DOS MM_UWIN 627 \ | | | / / / 628 ------------------------------------------------ 629 | | 630 MM_Unix | 631 | | 632 MM_Any 633 634NOTE: Each direct L<MM_Unix|ExtUtils::MM_Unix> subclass is also an 635L<MM_Any|ExtUtils::MM_Any> subclass. This 636is a temporary hack because MM_Unix overrides some MM_Any methods with 637Unix specific code. It allows the non-Unix modules to see the 638original MM_Any implementations. 639 640NOTE: Modules like L<File::Spec> and L<Exporter> have been omitted for clarity. 641 642=head1 PATCHING 643 644If you have a question you'd like to see added to the FAQ (whether or 645not you have the answer) please either: 646 647=over 2 648 649=item * make a pull request on the MakeMaker github repository 650 651=item * raise a issue on the MakeMaker github repository 652 653=item * file an RT ticket 654 655=item * email makemaker@perl.org 656 657=back 658 659=head1 AUTHOR 660 661The denizens of makemaker@perl.org. 662 663=head1 SEE ALSO 664 665L<ExtUtils::MakeMaker> 666 667=cut 668