m4/pdns_relro.m4

   1 dnl
   2 dnl Check for -z now and -z relro linker flags
   3 dnl
   4 dnl Copyright (C) 2013 Red Hat, Inc.
   5 dnl
   6 dnl This library is free software; you can redistribute it and/or
   7 dnl modify it under the terms of the GNU Lesser General Public
   8 dnl License as published by the Free Software Foundation; either
   9 dnl version 2.1 of the License, or (at your option) any later version.
  10 dnl
  11 dnl This library is distributed in the hope that it will be useful,
  12 dnl but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 dnl MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 dnl Lesser General Public License for more details.
  15 dnl
  16 dnl You should have received a copy of the GNU Lesser General Public
  17 dnl License along with this library.  If not, see
  18 dnl <http://www.gnu.org/licenses/>.
  19 dnl
  20
  21 AC_DEFUN([AC_LD_RELRO],[
  22     AC_MSG_CHECKING([for how to force completely read-only GOT table])
  23
  24     RELRO_LDFLAGS=
  25     ld_help=`$CXX -Wl,-help 2>&1`
  26     case $ld_help in
  27         *"-z relro"*) RELRO_LDFLAGS="-Wl,-z -Wl,relro" ;;
  28     esac
  29     case $ld_help in
  30         *"-z now"*) RELRO_LDFLAGS="$RELRO_LDFLAGS -Wl,-z -Wl,now" ;;
  31     esac
  32     AC_SUBST([RELRO_LDFLAGS])
  33     AS_IF([test "x$RELRO_LDFLAGS" != "x"],
  34       [AC_MSG_RESULT([$RELRO_LDFLAGS])],
  35       [AC_MSG_RESULT([unknown])]
  36     )
  37 ])