| # noexecstack.m4 |
| dnl Copyright (C) 1995-2006 Free Software Foundation, Inc. |
| dnl |
| dnl This library is free software; you can redistribute it and/or |
| dnl modify it under the terms of the GNU Lesser General Public |
| dnl License as published by the Free Software Foundation; either |
| dnl version 2.1 of the License, or (at your option) any later version. |
| dnl |
| dnl This library is distributed in the hope that it will be useful, |
| dnl but WITHOUT ANY WARRANTY; without even the implied warranty of |
| dnl MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| dnl Lesser General Public License for more details. |
| dnl |
| dnl You should have received a copy of the GNU Lesser General Public |
| dnl License along with this library; if not, write to the Free Software |
| dnl Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| |
| dnl Checks whether the stack can be marked nonexecutable by passing an |
| dnl option to the C-compiler when acting on .s files. Returns that |
| dnl option in NOEXECSTACK_FLAGS. |
| dnl This macro is adapted from one found in GLIBC-2.3.5. |
| AC_DEFUN([CL_AS_NOEXECSTACK],[ |
| AC_REQUIRE([AC_PROG_CC]) |
| AC_REQUIRE([AM_PROG_AS]) |
| |
| AC_MSG_CHECKING([whether non excutable stack support is requested]) |
| AC_ARG_ENABLE(noexecstack, |
| AC_HELP_STRING([--disable-noexecstack], |
| [disable non executable stack support]), |
| noexecstack_support=$enableval, noexecstack_support=yes) |
| AC_MSG_RESULT($noexecstack_support) |
| |
| AC_CACHE_CHECK([whether assembler supports --noexecstack option], |
| cl_cv_as_noexecstack, [dnl |
| cat > conftest.c <<EOF |
| void foo() {} |
| EOF |
| if AC_TRY_COMMAND([${CC} $CFLAGS $CPPFLAGS |
| -S -o conftest.s conftest.c >/dev/null]) \ |
| && grep .note.GNU-stack conftest.s >/dev/null \ |
| && AC_TRY_COMMAND([${CCAS} $CCASFLAGS $CPPFLAGS -Wa,--noexecstack |
| -c -o conftest.o conftest.s >/dev/null]) |
| then |
| cl_cv_as_noexecstack=yes |
| else |
| cl_cv_as_noexecstack=no |
| fi |
| rm -f conftest*]) |
| if test "$noexecstack_support" = yes -a "$cl_cv_as_noexecstack" = yes; then |
| NOEXECSTACK_FLAGS="-Wa,--noexecstack" |
| else |
| NOEXECSTACK_FLAGS= |
| fi |
| AC_SUBST(NOEXECSTACK_FLAGS) |
| ]) |
