1If you read this file _as_is_, just ignore the funny characters you see.
2It is written in the POD format (see pod/perlpod.pod) which is specially
3designed to be readable as is.
4
5=head1 NAME
6
7perlmacosx - Perl under Mac OS X
8
9=head1 SYNOPSIS
10
11This document briefly describes Perl under Mac OS X.
12
13  curl -O https://www.cpan.org/src/perl-5.35.5.tar.gz
14  tar -xzf perl-5.35.5.tar.gz
15  cd perl-5.35.5
16  ./Configure -des -Dprefix=/usr/local/
17  make
18  make test
19  sudo make install
20
21=head1 DESCRIPTION
22
23The latest Perl release (5.35.5 as of this writing) builds without changes
24under all versions of Mac OS X from 10.3 "Panther" onwards.
25
26In order to build your own version of Perl you will need 'make',
27which is part of Apple's developer tools - also known as Xcode. From
28Mac OS X 10.7 "Lion" onwards, it can be downloaded separately as the
29'Command Line Tools' bundle directly from L<https://developer.apple.com/downloads/>
30(you will need a free account to log in), or as a part of the Xcode suite,
31freely available at the App Store. Xcode is a pretty big app, so
32unless you already have it or really want it, you are advised to get the
33'Command Line Tools' bundle separately from the link above. If you want
34to do it from within Xcode, go to Xcode -> Preferences -> Downloads and
35select the 'Command Line Tools' option.
36
37Between Mac OS X 10.3 "Panther" and 10.6 "Snow Leopard", the 'Command
38Line Tools' bundle was called 'unix tools', and was usually supplied
39with Mac OS install DVDs.
40
41Earlier Mac OS X releases (10.2 "Jaguar" and older) did not include a
42completely thread-safe libc, so threading is not fully supported. Also,
43earlier releases included a buggy libdb, so some of the DB_File tests
44are known to fail on those releases.
45
46
47=head2 Installation Prefix
48
49The default installation location for this release uses the traditional
50UNIX directory layout under /usr/local. This is the recommended location
51for most users, and will leave the Apple-supplied Perl and its modules
52undisturbed.
53
54Using an installation prefix of '/usr' will result in a directory layout
55that mirrors that of Apple's default Perl, with core modules stored in
56'/System/Library/Perl/${version}', CPAN modules stored in
57'/Library/Perl/${version}', and the addition of
58'/Network/Library/Perl/${version}' to @INC for modules that are stored
59on a file server and used by many Macs.
60
61
62=head2 SDK support
63
64First, export the path to the SDK into the build environment:
65
66 export SDK=/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.8.sdk
67
68Please make sure the SDK version (i.e. the numbers right before '.sdk')
69matches your system's (in this case, Mac OS X 10.8 "Mountain Lion"), as it is
70possible to have more than one SDK installed. Also make sure the path exists
71in your system, and if it doesn't please make sure the SDK is properly
72installed, as it should come with the 'Command Line Tools' bundle mentioned
73above. Finally, if you have an older Mac OS X (10.6 "Snow Leopard" and below)
74running Xcode 4.2 or lower, the SDK path might be something like
75C<'/Developer/SDKs/MacOSX10.3.9.sdk'>.
76
77You can use the SDK by exporting some additions to Perl's 'ccflags' and '..flags'
78config variables:
79
80    ./Configure -Accflags="-nostdinc -B$SDK/usr/include/gcc \
81                           -B$SDK/usr/lib/gcc -isystem$SDK/usr/include \
82                           -F$SDK/System/Library/Frameworks" \
83                -Aldflags="-Wl,-syslibroot,$SDK" \
84                -de
85
86=head2 Universal Binary support
87
88Note: From Mac OS X 10.6 "Snow Leopard" onwards, Apple only supports
89Intel-based hardware. This means you can safely skip this section unless
90you have an older Apple computer running on ppc or wish to create a perl
91binary with backwards compatibility.
92
93You can compile perl as a universal binary (built for both ppc and intel).
94In Mac OS X 10.4 "Tiger", you must export the 'u' variant of the SDK:
95
96    export SDK=/Developer/SDKs/MacOSX10.4u.sdk
97
98Mac OS X 10.5 "Leopard" and above do not require the 'u' variant.
99
100In addition to the compiler flags used to select the SDK, also add the flags
101for creating a universal binary:
102
103 ./Configure -Accflags="-arch i686 -arch ppc -nostdinc               \
104                         -B$SDK/usr/include/gcc                      \
105                        -B$SDK/usr/lib/gcc -isystem$SDK/usr/include  \
106                        -F$SDK/System/Library/Frameworks"            \
107             -Aldflags="-arch i686 -arch ppc -Wl,-syslibroot,$SDK"   \
108             -de
109
110Keep in mind that these compiler and linker settings will also be used when
111building CPAN modules. For XS modules to be compiled as a universal binary, any
112libraries it links to must also be universal binaries. The system libraries that
113Apple includes with the 10.4u SDK are all universal, but user-installed libraries
114may need to be re-installed as universal binaries.
115
116=head2 64-bit PPC support
117
118Follow the instructions in F<INSTALL> to build perl with support for 64-bit
119integers (C<use64bitint>) or both 64-bit integers and 64-bit addressing
120(C<use64bitall>). In the latter case, the resulting binary will run only
121on G5-based hosts.
122
123Support for 64-bit addressing is experimental: some aspects of Perl may be
124omitted or buggy. Note the messages output by F<Configure> for further
125information. Please use L<https://github.com/Perl/perl5/issues> to submit a
126problem report in the event that you encounter difficulties.
127
128When building 64-bit modules, it is your responsibility to ensure that linked
129external libraries and frameworks provide 64-bit support: if they do not,
130module building may appear to succeed, but attempts to use the module will
131result in run-time dynamic linking errors, and subsequent test failures.
132You can use C<file> to discover the architectures supported by a library:
133
134    $ file libgdbm.3.0.0.dylib
135    libgdbm.3.0.0.dylib: Mach-O fat file with 2 architectures
136    libgdbm.3.0.0.dylib (for architecture ppc):      Mach-O dynamically linked shared library ppc
137    libgdbm.3.0.0.dylib (for architecture ppc64):    Mach-O 64-bit dynamically linked shared library ppc64
138
139Note that this issue precludes the building of many Macintosh-specific CPAN
140modules (C<Mac::*>), as the required Apple frameworks do not provide PPC64
141support. Similarly, downloads from Fink or Darwinports are unlikely to provide
14264-bit support; the libraries must be rebuilt from source with the appropriate
143compiler and linker flags. For further information, see Apple's
144I<64-Bit Transition Guide> at
145L<https://developer.apple.com/library/archive/documentation/Darwin/Conceptual/64bitPorting/transition/transition.html>.
146
147=head2 libperl and Prebinding
148
149Mac OS X ships with a dynamically-loaded libperl, but the default for
150this release is to compile a static libperl. The reason for this is
151pre-binding. Dynamic libraries can be pre-bound to a specific address in
152memory in order to decrease load time. To do this, one needs to be aware
153of the location and size of all previously-loaded libraries. Apple
154collects this information as part of their overall OS build process, and
155thus has easy access to it when building Perl, but ordinary users would
156need to go to a great deal of effort to obtain the information needed
157for pre-binding.
158
159You can override the default and build a shared libperl if you wish
160(S<Configure ... -Duseshrplib>).
161
162With Mac OS X 10.4 "Tiger" and newer, there is almost no performance
163penalty for non-prebound libraries. Earlier releases will suffer a greater
164load time than either the static library, or Apple's pre-bound dynamic library.
165
166=head2 Updating Apple's Perl
167
168In a word - don't, at least not without a *very* good reason. Your scripts
169can just as easily begin with "#!/usr/local/bin/perl" as with
170"#!/usr/bin/perl". Scripts supplied by Apple and other third parties as
171part of installation packages and such have generally only been tested
172with the /usr/bin/perl that's installed by Apple.
173
174If you find that you do need to update the system Perl, one issue worth
175keeping in mind is the question of static vs. dynamic libraries. If you
176upgrade using the default static libperl, you will find that the dynamic
177libperl supplied by Apple will not be deleted. If both libraries are
178present when an application that links against libperl is built, ld will
179link against the dynamic library by default. So, if you need to replace
180Apple's dynamic libperl with a static libperl, you need to be sure to
181delete the older dynamic library after you've installed the update.
182
183
184=head2 Known problems
185
186If you have installed extra libraries such as GDBM through Fink
187(in other words, you have libraries under F</sw/lib>), or libdlcompat
188to F</usr/local/lib>, you may need to be extra careful when running
189Configure to not to confuse Configure and Perl about which libraries
190to use.  Being confused will show up for example as "dyld" errors about
191symbol problems, for example during "make test". The safest bet is to run
192Configure as
193
194    Configure ... -Uloclibpth -Dlibpth=/usr/lib
195
196to make Configure look only into the system libraries.  If you have some
197extra library directories that you really want to use (such as newer
198Berkeley DB libraries in pre-Panther systems), add those to the libpth:
199
200    Configure ... -Uloclibpth -Dlibpth='/usr/lib /opt/lib'
201
202The default of building Perl statically may cause problems with complex
203applications like Tk: in that case consider building shared Perl
204
205    Configure ... -Duseshrplib
206
207but remember that there's a startup cost to pay in that case (see above
208"libperl and Prebinding").
209
210Starting with Tiger (Mac OS X 10.4), Apple shipped broken locale files for
211the eu_ES locale (Basque-Spain).  In previous releases of Perl, this resulted in
212failures in the F<lib/locale> test. These failures have been suppressed
213in the current release of Perl by making the test ignore the broken locale.
214If you need to use the eu_ES locale, you should contact Apple support.
215
216
217=head2 Cocoa
218
219There are two ways to use Cocoa from Perl. Apple's PerlObjCBridge
220module, included with Mac OS X, can be used by standalone scripts to
221access Foundation (i.e. non-GUI) classes and objects.
222
223An alternative is CamelBones, a framework that allows access to both
224Foundation and AppKit classes and objects, so that full GUI applications
225can be built in Perl. CamelBones can be found on SourceForge, at
226L<https://www.sourceforge.net/projects/camelbones/>.
227
228
229=head1 Starting From Scratch
230
231Unfortunately it is not that difficult somehow manage to break one's
232Mac OS X Perl rather severely.  If all else fails and you want to
233really, B<REALLY>, start from scratch and remove even your Apple Perl
234installation (which has become corrupted somehow), the following
235instructions should do it.  B<Please think twice before following
236these instructions: they are much like conducting brain surgery to
237yourself.  Without anesthesia.>  We will B<not> come to fix your system
238if you do this.
239
240First, get rid of the libperl.dylib:
241
242    # cd /System/Library/Perl/darwin/CORE
243    # rm libperl.dylib
244
245Then delete every .bundle file found anywhere in the folders:
246
247    /System/Library/Perl
248    /Library/Perl
249
250You can find them for example by
251
252    # find /System/Library/Perl /Library/Perl -name '*.bundle' -print
253
254After this you can either copy Perl from your operating system media
255(you will need at least the /System/Library/Perl and /usr/bin/perl),
256or rebuild Perl from the source code with C<Configure -Dprefix=/usr
257-Duseshrplib> NOTE: the C<-Dprefix=/usr> to replace the system Perl
258works much better with Perl 5.8.1 and later, in Perl 5.8.0 the
259settings were not quite right.
260
261"Pacifist" from CharlesSoft (L<https://www.charlessoft.com/>) is a nice
262way to extract the Perl binaries from the OS media, without having to
263reinstall the entire OS.
264
265
266=head1 AUTHOR
267
268This README was written by Sherm Pendley E<lt>sherm@dot-app.orgE<gt>,
269and subsequently updated by Dominic Dunlop E<lt>domo@computer.orgE<gt>
270and Breno G. de Oliveira E<lt>garu@cpan.orgE<gt>. The "Starting From Scratch"
271recipe was contributed by John Montbriand E<lt>montbriand@apple.comE<gt>.
272
273=head1 DATE
274
275Last modified 2013-04-29.
276