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1 | package ExtUtils::MakeMaker::FAQ; |
2 | |
3 | our $VERSION = '0.02'; |
4 | |
5 | 1; |
6 | __END__ |
7 | |
8 | =head1 NAME |
9 | |
10 | ExtUtils::MakeMaker::FAQ - Frequently Asked Questions About MakeMaker |
11 | |
12 | =head1 DESCRIPTION |
13 | |
14 | FAQs, tricks and tips for C<ExtUtils::MakeMaker>. |
15 | |
16 | =head2 Philosophy and History |
17 | |
18 | =over 4 |
19 | |
20 | =item Why not just use <insert other build config tool here>? |
21 | |
22 | Why did MakeMaker reinvent the build configuration wheel? Why not |
23 | just use autoconf or automake or ppm or Ant or ... |
24 | |
25 | There are many reasons, but the major one is cross-platform |
26 | compatibility. |
27 | |
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. |
32 | |
33 | No such build tool existed at the time and I only know of one now |
34 | (Module::Build). |
35 | |
36 | |
37 | =item What's Module::Build and how does it relate to MakeMaker? |
38 | |
39 | Module::Build is a project by Ken Williams to supplant MakeMaker. |
40 | Its primary advantages are: |
41 | |
42 | =over 8 |
43 | |
44 | =item * pure perl. no make, no shell commands |
45 | |
46 | =item * easier to customize |
47 | |
48 | =item * cleaner internals |
49 | |
50 | =item * less cruft |
51 | |
52 | =back |
53 | |
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 |
56 | MakeMaker. |
57 | |
58 | =back |
59 | |
60 | =head2 XS |
61 | |
62 | =over 4 |
63 | |
64 | =item How do I make two or more XS files coexist in the same directory? |
65 | |
66 | Sometimes you need to have two and more XS files in the same package. |
67 | One way to go is to put them into separate directories, but sometimes |
68 | this is not the most suitable solution. The following technique allows |
69 | you to put two (and more) XS files in the same directory. |
70 | |
71 | Let's assume that we have a package C<Cool::Foo>, which includes |
72 | C<Cool::Foo> and C<Cool::Bar> modules each having a separate XS |
73 | file. First we use the following I<Makefile.PL>: |
74 | |
75 | use ExtUtils::MakeMaker; |
76 | |
77 | WriteMakefile( |
78 | NAME => 'Cool::Foo', |
79 | VERSION_FROM => 'Foo.pm', |
80 | OBJECT => q/$(O_FILES)/, |
81 | # ... other attrs ... |
82 | ); |
83 | |
84 | Notice the C<OBJECT> attribute. MakeMaker generates the following |
85 | variables in I<Makefile>: |
86 | |
87 | # Handy lists of source code files: |
88 | XS_FILES= Bar.xs \ |
89 | Foo.xs |
90 | C_FILES = Bar.c \ |
91 | Foo.c |
92 | O_FILES = Bar.o \ |
93 | Foo.o |
94 | |
95 | Therefore we can use the C<O_FILES> variable to tell MakeMaker to use |
96 | these objects into the shared library. |
97 | |
98 | That's pretty much it. Now write I<Foo.pm> and I<Foo.xs>, I<Bar.pm> |
99 | and I<Bar.xs>, where I<Foo.pm> bootstraps the shared library and |
100 | I<Bar.pm> simply loading I<Foo.pm>. |
101 | |
102 | The only issue left is to how to bootstrap I<Bar.xs>. This is done |
103 | from I<Foo.xs>: |
104 | |
105 | MODULE = Cool::Foo PACKAGE = Cool::Foo |
106 | |
107 | BOOT: |
108 | # boot the second XS file |
109 | boot_Cool__Bar(aTHX_ cv); |
110 | |
111 | If you have more than two files, this is the place where you should |
112 | boot extra XS files from. |
113 | |
114 | The following four files sum up all the details discussed so far. |
115 | |
116 | Foo.pm: |
117 | ------- |
118 | package Cool::Foo; |
119 | |
120 | require DynaLoader; |
121 | |
122 | our @ISA = qw(DynaLoader); |
123 | our $VERSION = '0.01'; |
124 | bootstrap Cool::Foo $VERSION; |
125 | |
126 | 1; |
127 | |
128 | Bar.pm: |
129 | ------- |
130 | package Cool::Bar; |
131 | |
132 | use Cool::Foo; # bootstraps Bar.xs |
133 | |
134 | 1; |
135 | |
136 | Foo.xs: |
137 | ------- |
138 | #include "EXTERN.h" |
139 | #include "perl.h" |
140 | #include "XSUB.h" |
141 | |
142 | MODULE = Cool::Foo PACKAGE = Cool::Foo |
143 | |
144 | BOOT: |
145 | # boot the second XS file |
146 | boot_Cool__Bar(aTHX_ cv); |
147 | |
148 | MODULE = Cool::Foo PACKAGE = Cool::Foo PREFIX = cool_foo_ |
149 | |
150 | void |
151 | cool_foo_perl_rules() |
152 | |
153 | CODE: |
154 | fprintf(stderr, "Cool::Foo says: Perl Rules\n"); |
155 | |
156 | Bar.xs: |
157 | ------- |
158 | #include "EXTERN.h" |
159 | #include "perl.h" |
160 | #include "XSUB.h" |
161 | |
162 | MODULE = Cool::Bar PACKAGE = Cool::Bar PREFIX = cool_bar_ |
163 | |
164 | void |
165 | cool_bar_perl_rules() |
166 | |
167 | CODE: |
168 | fprintf(stderr, "Cool::Bar says: Perl Rules\n"); |
169 | |
170 | And of course a very basic test: |
171 | |
172 | test.pl: |
173 | -------- |
174 | use Test; |
175 | BEGIN { plan tests => 1 }; |
176 | use Cool::Foo; |
177 | use Cool::Bar; |
178 | Cool::Foo::perl_rules(); |
179 | Cool::Bar::perl_rules(); |
180 | ok 1; |
181 | |
182 | This tip has been brought to you by Nick Ing-Simmons and Stas Bekman. |
183 | |
184 | =back |
185 | |
186 | =head1 PATCHING |
187 | |
188 | If you have a question you'd like to see added to the FAQ (whether or |
189 | not you have the answer) please send it to makemaker@perl.org. |
190 | |
191 | =head1 AUTHOR |
192 | |
193 | The denizens of makemaker@perl.org. |
194 | |
195 | =head1 SEE ALSO |
196 | |
197 | L<ExtUtils::MakeMaker> |
198 | |
199 | =cut |