m4/multiarch.m4

   1 # multiarch.m4 serial 7
   2 dnl Copyright (C) 2008-2014 Free Software Foundation, Inc.
   3 dnl This file is free software; the Free Software Foundation
   4 dnl gives unlimited permission to copy and/or distribute it,
   5 dnl with or without modifications, as long as this notice is preserved.
   6
   7 # Determine whether the compiler is or may be producing universal binaries.
   8 #
   9 # On Mac OS X 10.5 and later systems, the user can create libraries and
  10 # executables that work on multiple system types--known as "fat" or
  11 # "universal" binaries--by specifying multiple '-arch' options to the
  12 # compiler but only a single '-arch' option to the preprocessor.  Like
  13 # this:
  14 #
  15 #     ./configure CC="gcc -arch i386 -arch x86_64 -arch ppc -arch ppc64" \
  16 #                 CXX="g++ -arch i386 -arch x86_64 -arch ppc -arch ppc64" \
  17 #                 CPP="gcc -E" CXXCPP="g++ -E"
  18 #
  19 # Detect this situation and set APPLE_UNIVERSAL_BUILD accordingly.
  20
  21 AC_DEFUN_ONCE([gl_MULTIARCH],
  22 [
  23   dnl Code similar to autoconf-2.63 AC_C_BIGENDIAN.
  24   gl_cv_c_multiarch=no
  25   AC_COMPILE_IFELSE(
  26     [AC_LANG_SOURCE(
  27       [[#ifndef __APPLE_CC__
  28          not a universal capable compiler
  29         #endif
  30         typedef int dummy;
  31       ]])],
  32     [
  33      dnl Check for potential -arch flags.  It is not universal unless
  34      dnl there are at least two -arch flags with different values.
  35      arch=
  36      prev=
  37      for word in ${CC} ${CFLAGS} ${CPPFLAGS} ${LDFLAGS}; do
  38        if test -n "$prev"; then
  39          case $word in
  40            i?86 | x86_64 | ppc | ppc64)
  41              if test -z "$arch" || test "$arch" = "$word"; then
  42                arch="$word"
  43              else
  44                gl_cv_c_multiarch=yes
  45              fi
  46              ;;
  47          esac
  48          prev=
  49        else
  50          if test "x$word" = "x-arch"; then
  51            prev=arch
  52          fi
  53        fi
  54      done
  55     ])
  56   if test $gl_cv_c_multiarch = yes; then
  57     APPLE_UNIVERSAL_BUILD=1
  58   else
  59     APPLE_UNIVERSAL_BUILD=0
  60   fi
  61   AC_SUBST([APPLE_UNIVERSAL_BUILD])
  62 ])