projects/sample/autoconf/m4/link_options.m4

   1 #
   2 # Get the linker version string.
   3 #
   4 # This macro is specific to LLVM.
   5 #
   6 AC_DEFUN([AC_LINK_GET_VERSION],
   7   [AC_CACHE_CHECK([for linker version],[llvm_cv_link_version],
   8   [
   9    version_string="$(ld -v 2>&1 | head -1)"
  10
  11    # Check for ld64.
  12    if (echo "$version_string" | grep -q "ld64"); then
  13      llvm_cv_link_version=$(echo "$version_string" | sed -e "s#.*ld64-\([^ ]*\)\( (.*)\)\{0,1\}#\1#")
  14    else
  15      llvm_cv_link_version=$(echo "$version_string" | sed -e "s#[^0-9]*\([0-9.]*\).*#\1#")
  16    fi
  17   ])
  18   AC_DEFINE_UNQUOTED([HOST_LINK_VERSION],"$llvm_cv_link_version",
  19                      [Linker version detected at compile time.])
  20 ])
  21
  22 #
  23 # Determine if the system can handle the -R option being passed to the linker.
  24 #
  25 # This macro is specific to LLVM.
  26 #
  27 AC_DEFUN([AC_LINK_USE_R],
  28 [AC_CACHE_CHECK([for compiler -Wl,-R<path> option],[llvm_cv_link_use_r],
  29 [ AC_LANG_PUSH([C])
  30   oldcflags="$CFLAGS"
  31   CFLAGS="$CFLAGS -Wl,-R."
  32   AC_LINK_IFELSE([AC_LANG_PROGRAM([[]],[[]])],
  33     [llvm_cv_link_use_r=yes],[llvm_cv_link_use_r=no])
  34   CFLAGS="$oldcflags"
  35   AC_LANG_POP([C])
  36 ])
  37 if test "$llvm_cv_link_use_r" = yes ; then
  38   AC_DEFINE([HAVE_LINK_R],[1],[Define if you can use -Wl,-R. to pass -R. to the linker, in order to add the current directory to the dynamic linker search path.])
  39   fi
  40 ])
  41
  42 #
  43 # Determine if the system can handle the -R option being passed to the linker.
  44 #
  45 # This macro is specific to LLVM.
  46 #
  47 AC_DEFUN([AC_LINK_EXPORT_DYNAMIC],
  48 [AC_CACHE_CHECK([for compiler -Wl,-export-dynamic option],
  49                 [llvm_cv_link_use_export_dynamic],
  50 [ AC_LANG_PUSH([C])
  51   oldcflags="$CFLAGS"
  52   CFLAGS="$CFLAGS -Wl,-export-dynamic"
  53   AC_LINK_IFELSE([AC_LANG_PROGRAM([[]],[[]])],
  54     [llvm_cv_link_use_export_dynamic=yes],[llvm_cv_link_use_export_dynamic=no])
  55   CFLAGS="$oldcflags"
  56   AC_LANG_POP([C])
  57 ])
  58 if test "$llvm_cv_link_use_export_dynamic" = yes ; then
  59   AC_DEFINE([HAVE_LINK_EXPORT_DYNAMIC],[1],[Define if you can use -Wl,-export-dynamic.])
  60   fi
  61 ])
  62
  63 #
  64 # Determine if the system can handle the --version-script option being
  65 # passed to the linker.
  66 #
  67 # This macro is specific to LLVM.
  68 #
  69 AC_DEFUN([AC_LINK_VERSION_SCRIPT],
  70 [AC_CACHE_CHECK([for compiler -Wl,--version-script option],
  71                 [llvm_cv_link_use_version_script],
  72 [ AC_LANG_PUSH([C])
  73   oldcflags="$CFLAGS"
  74
  75   # The following code is from the autoconf manual,
  76   # "11.13: Limitations of Usual Tools".
  77   # Create a temporary directory $tmp in $TMPDIR (default /tmp).
  78   # Use mktemp if possible; otherwise fall back on mkdir,
  79   # with $RANDOM to make collisions less likely.
  80   : ${TMPDIR=/tmp}
  81   {
  82     tmp=`
  83       (umask 077 && mktemp -d "$TMPDIR/fooXXXXXX") 2>/dev/null
  84     ` &&
  85     test -n "$tmp" && test -d "$tmp"
  86   } || {
  87     tmp=$TMPDIR/foo$$-$RANDOM
  88     (umask 077 && mkdir "$tmp")
  89   } || exit $?
  90
  91   echo "{" > "$tmp/export.map"
  92   echo "  global: main;" >> "$tmp/export.map"
  93   echo "  local: *;" >> "$tmp/export.map"
  94   echo "};" >> "$tmp/export.map"
  95
  96   CFLAGS="$CFLAGS -Wl,--version-script=$tmp/export.map"
  97   AC_LINK_IFELSE([AC_LANG_PROGRAM([[]],[[]])],
  98     [llvm_cv_link_use_version_script=yes],[llvm_cv_link_use_version_script=no])
  99   rm "$tmp/export.map"
 100   rmdir "$tmp"
 101   CFLAGS="$oldcflags"
 102   AC_LANG_POP([C])
 103 ])
 104 if test "$llvm_cv_link_use_version_script" = yes ; then
 105   AC_SUBST(HAVE_LINK_VERSION_SCRIPT,1)
 106   fi
 107 ])
 108