gnulib/import/m4/multiarch.m4

   1 # multiarch.m4 serial 9
   2 dnl Copyright (C) 2008-2021 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   AC_CACHE_CHECK([whether the compiler produces multi-arch binaries],
  25     [gl_cv_c_multiarch],
  26     [gl_cv_c_multiarch=no
  27      AC_COMPILE_IFELSE(
  28        [AC_LANG_SOURCE(
  29          [[#ifndef __APPLE_CC__
  30             not a universal capable compiler
  31            #endif
  32            typedef int dummy;
  33          ]])],
  34        [
  35         dnl Check for potential -arch flags.  It is not universal unless
  36         dnl there are at least two -arch flags with different values.
  37         arch=
  38         prev=
  39         for word in ${CC} ${CFLAGS} ${CPPFLAGS} ${LDFLAGS}; do
  40           if test -n "$prev"; then
  41             case $word in
  42               i?86 | x86_64 | ppc | ppc64 | arm | arm64)
  43                 if test -z "$arch" || test "$arch" = "$word"; then
  44                   arch="$word"
  45                 else
  46                   gl_cv_c_multiarch=yes
  47                 fi
  48                 ;;
  49             esac
  50             prev=
  51           else
  52             if test "x$word" = "x-arch"; then
  53               prev=arch
  54             fi
  55           fi
  56         done
  57        ])
  58     ])
  59   if test $gl_cv_c_multiarch = yes; then
  60     APPLE_UNIVERSAL_BUILD=1
  61   else
  62     APPLE_UNIVERSAL_BUILD=0
  63   fi
  64   AC_SUBST([APPLE_UNIVERSAL_BUILD])
  65 ])