# multiarch.m4 serial 7

dnl Copyright (C) 2008-2015 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 Mac OS 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 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

    APPLE_UNIVERSAL_BUILD=1

  else

    APPLE_UNIVERSAL_BUILD=0

  fi

  AC_SUBST([APPLE_UNIVERSAL_BUILD])

])