Hi,
On MacOS X 10.5, most system-provided binaries and libraries are "fat" or
"universal": they can be executed on all architectures of MacOS X 10.5.
Given the section "Compiling For Multiple Architectures" from the INSTALL
file of so many GNU packages, I was under the impression that it was hard
to build universal binaries for packages that use autoconf. But this is
actually not the case. Among the 4 packages I tested (libiconv, libsigsegv,
gettext, gperf), all but one can be built as universal binaries out of the box,
given the appropriate instructions, and the one that did not work (libsigsegv)
could be made to work in 20 minutes.
This is clearly not optimally documented. The location where it should be
documented, IMO, is the INSTALL file. Here is a patch which adds a third
paragraph to the section "Compiling For Multiple Architectures":
On MacOS X systems, you can create libraries and executables that work
on multiple system types - known as "fat" or "universal" binaries - by
specifying multiple '-arch' options to the compiler but only a single
'-arch' option to the preprocessor. Like this:
env CC="gcc -arch i386 -arch x86_64 -arch ppc -arch ppc64" \
CXX="g++ -arch i386 -arch x86_64 -arch ppc -arch ppc64" \
CPP="gcc -arch ppc -E" \
CXXCPP="g++ -arch ppc -E" \
./configure
Here's the proposed patch.
2008-08-17 Bruno Haible <bruno@xxxxxxxxx>
* doc/install.texi (Compiling For Multiple Architectures): Explain how
to create universal binaries on MacOS X.
--- doc/install.texi.bak 2008-03-14 01:46:05.000000000 +0100
+++ doc/install.texi 2008-08-17 11:33:19.000000000 +0200
@@ -6,7 +6,7 @@
@unnumbered Installation Instructions
Copyright @copyright{} 1994, 1995, 1996, 1999, 2000, 2001, 2002, 2004,
-2005, 2006, 2007 Free Software Foundation, Inc.
+2005, 2006, 2007, 2008 Free Software Foundation, Inc.
This file is free documentation; the Free Software Foundation gives
unlimited permission to copy, distribute and modify it.
@@ -120,6 +120,19 @@
installed the package for one architecture, use @samp{make distclean}
before reconfiguring for another architecture.
+On MacOS X systems, you can create libraries and executables that work
+on multiple system types -- known as "fat" or "universal" binaries --
+by specifying multiple @option{-arch} options to the compiler but only
+a single @option{-arch} option to the preprocessor. Like this:
+
+@example
+env CC="gcc -arch i386 -arch x86_64 -arch ppc -arch ppc64" \
+ CXX="g++ -arch i386 -arch x86_64 -arch ppc -arch ppc64" \
+ CPP="gcc -arch ppc -E" \
+ CXXCPP="g++ -arch ppc -E" \
+ ./configure
+@end example
+
@node Installation Names
@section Installation Names
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