# multiarch.m4 serial 5

dnl Copyright (C) 2008, 2009, 2010 Free Software Foundation, Inc.

dnl This file is free software; the Free Software Foundation

dnl gives unlimited permission to copy and/or distribute it,

dnl with or without modifications, as long as this notice is preserved.

# Determine whether the compiler is or may be producing universal binaries.

#

# On MacOS X 10.5 and later systems, the user 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:

#

# ./configure CC="gcc -arch i386 -arch x86_64 -arch ppc -arch ppc64" \

# CXX="g++ -arch i386 -arch x86_64 -arch ppc -arch ppc64" \

# CPP="gcc -E" CXXCPP="g++ -E"

#

# Detect this situation and set the macro AA_APPLE_UNIVERSAL_BUILD at the

# beginning of config.h and set APPLE_UNIVERSAL_BUILD accordingly.

AC_DEFUN_ONCE([gl_MULTIARCH],

[

dnl Code similar to autoconf-2.63 AC_C_BIGENDIAN.

gl_cv_c_multiarch=no

AC_COMPILE_IFELSE(

[AC_LANG_SOURCE(

[[#ifndef __APPLE_CC__

not a universal capable compiler

#endif

typedef int dummy;

]])],

[

dnl Check for potential -arch flags. It is not universal unless

dnl there are at least two -arch flags with different values.

arch=

prev=

for word in ${CC} ${CFLAGS} ${CPPFLAGS} ${LDFLAGS}; do

if test -n "$prev"; then

case $word in

i?86 | x86_64 | ppc | ppc64)

if test -z "$arch" || test "$arch" = "$word"; then

arch="$word"

else

gl_cv_c_multiarch=yes

fi

;;

esac

prev=

else

if test "x$word" = "x-arch"; then

prev=arch

fi

fi

done

])

if test $gl_cv_c_multiarch = yes; then

AC_DEFINE([AA_APPLE_UNIVERSAL_BUILD], [1],

[Define if the compiler is building for multiple architectures of Apple platforms at once.])

APPLE_UNIVERSAL_BUILD=1

else

APPLE_UNIVERSAL_BUILD=0

fi

AC_SUBST([APPLE_UNIVERSAL_BUILD])

])