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:-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 "$llvm_cv_link_use_r" = yes ; then
  38   AC_DEFINE([HAVE_LINK_R],[1],[Define if you can use -Wl,-R. to pass -R. to the linker, in order to add the current directory to the dynamic linker search path.])
  39   fi
  40 ])
  41
  42 #
  43 # Determine if the system can handle the -rdynamic option being passed
  44 # to the compiler.
  45 #
  46 # This macro is specific to LLVM.
  47 #
  48 AC_DEFUN([AC_LINK_EXPORT_DYNAMIC],
  49 [AC_CACHE_CHECK([for compiler -rdynamic option],
  50                 [llvm_cv_link_use_export_dynamic],
  51 [ AC_LANG_PUSH([C])
  52   oldcflags="$CFLAGS"
  53   CFLAGS="$CFLAGS -rdynamic"
  54   AC_LINK_IFELSE([AC_LANG_PROGRAM([[]],[[]])],
  55     [llvm_cv_link_use_export_dynamic=yes],[llvm_cv_link_use_export_dynamic=no])
  56   CFLAGS="$oldcflags"
  57   AC_LANG_POP([C])
  58 ])
  59 if test "$llvm_cv_link_use_export_dynamic" = yes ; then
  60   AC_DEFINE([HAVE_LINK_EXPORT_DYNAMIC],[1],[Define if you can use -rdynamic.])
  61   fi
  62 ])
  63
  64 #
  65 # Determine if the system can handle the --version-script option being
  66 # passed to the linker.
  67 #
  68 # This macro is specific to LLVM.
  69 #
  70 AC_DEFUN([AC_LINK_VERSION_SCRIPT],
  71 [AC_CACHE_CHECK([for compiler -Wl,--version-script option],
  72                 [llvm_cv_link_use_version_script],
  73 [ AC_LANG_PUSH([C])
  74   oldcflags="$CFLAGS"
  75
  76   # The following code is from the autoconf manual,
  77   # "11.13: Limitations of Usual Tools".
  78   # Create a temporary directory $tmp in $TMPDIR (default /tmp).
  79   # Use mktemp if possible; otherwise fall back on mkdir,
  80   # with $RANDOM to make collisions less likely.
  81   : ${TMPDIR=/tmp}
  82   {
  83     tmp=`
  84       (umask 077 && mktemp -d "$TMPDIR/fooXXXXXX") 2>/dev/null
  85     ` &&
  86     test -n "$tmp" && test -d "$tmp"
  87   } || {
  88     tmp=$TMPDIR/foo$$-$RANDOM
  89     (umask 077 && mkdir "$tmp")
  90   } || exit $?
  91
  92   echo "{" > "$tmp/export.map"
  93   echo "  global: main;" >> "$tmp/export.map"
  94   echo "  local: *;" >> "$tmp/export.map"
  95   echo "};" >> "$tmp/export.map"
  96
  97   CFLAGS="$CFLAGS -Wl,--version-script=$tmp/export.map"
  98   AC_LINK_IFELSE([AC_LANG_PROGRAM([[]],[[]])],
  99     [llvm_cv_link_use_version_script=yes],[llvm_cv_link_use_version_script=no])
 100   rm "$tmp/export.map"
 101   rmdir "$tmp"
 102   CFLAGS="$oldcflags"
 103   AC_LANG_POP([C])
 104 ])
 105 if test "$llvm_cv_link_use_version_script" = yes ; then
 106   AC_SUBST(HAVE_LINK_VERSION_SCRIPT,1)
 107   fi
 108 ])
 109