Chris@40: dnl Copyright (C) 2013  Xiph.org Foundation
Chris@40: dnl
Chris@40: dnl Redistribution and use in source and binary forms, with or without
Chris@40: dnl modification, are permitted provided that the following conditions
Chris@40: dnl are met:
Chris@40: dnl
Chris@40: dnl - Redistributions of source code must retain the above copyright
Chris@40: dnl notice, this list of conditions and the following disclaimer.
Chris@40: dnl
Chris@40: dnl - Redistributions in binary form must reproduce the above copyright
Chris@40: dnl notice, this list of conditions and the following disclaimer in the
Chris@40: dnl documentation and/or other materials provided with the distribution.
Chris@40: dnl
Chris@40: dnl - Neither the name of the Xiph.org Foundation nor the names of its
Chris@40: dnl contributors may be used to endorse or promote products derived from
Chris@40: dnl this software without specific prior written permission.
Chris@40: dnl
Chris@40: dnl THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
Chris@40: dnl ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
Chris@40: dnl LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
Chris@40: dnl A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR
Chris@40: dnl CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
Chris@40: dnl EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
Chris@40: dnl PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
Chris@40: dnl PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
Chris@40: dnl LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
Chris@40: dnl NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
Chris@40: dnl SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
Chris@40: 
Chris@40: dnl Want to know of GCC stack protector works, botfor the C and for the C++
Chris@40: dnl compiler.
Chris@40: dnl
Chris@40: dnl Just checking if the compiler accepts the required CFLAGSs is not enough
Chris@40: dnl because we have seen at least one instance where this check was
Chris@40: dnl in-sufficient.
Chris@40: dnl
Chris@40: dnl Instead, try to compile and link a test program with the stack protector
Chris@40: dnl flags. If that works, we use it.
Chris@40: 
Chris@40: AC_DEFUN([XIPH_GCC_STACK_PROTECTOR],
Chris@40: [AC_LANG_ASSERT(C)
Chris@40: 	AC_MSG_CHECKING([if $CC supports stack smash protection])
Chris@40: 	xiph_stack_check_old_cflags="$CFLAGS"
Chris@40: 	SSP_FLAGS="-fstack-protector --param ssp-buffer-size=4"
Chris@40: 	CFLAGS=$SSP_FLAGS
Chris@40: 	AC_TRY_LINK([
Chris@40: 			#include <stdio.h>
Chris@40: 			],
Chris@40: 		[puts("Hello, World!"); return 0;],
Chris@40: 		AC_MSG_RESULT([yes])
Chris@40: 			CFLAGS="$xiph_stack_check_old_cflags $SSP_FLAGS",
Chris@40: 		AC_MSG_RESULT([no])
Chris@40: 			CFLAGS="$xiph_stack_check_old_cflags"
Chris@40: 		)
Chris@40: ])# XIPH_GCC_STACK_PROTECTOR
Chris@40: 
Chris@40: AC_DEFUN([XIPH_GXX_STACK_PROTECTOR],
Chris@40: [AC_LANG_PUSH([C++])
Chris@40: 	AC_MSG_CHECKING([if $CXX supports stack smash protection])
Chris@40: 	xiph_stack_check_old_cflags="$CFLAGS"
Chris@40: 	SSP_FLAGS="-fstack-protector --param ssp-buffer-size=4"
Chris@40: 	CFLAGS=$SSP_FLAGS
Chris@40: 	AC_TRY_LINK([
Chris@40: 			#include <cstdio>
Chris@40: 			],
Chris@40: 		[puts("Hello, World!"); return 0;],
Chris@40: 		AC_MSG_RESULT([yes])
Chris@40: 			CFLAGS="$xiph_stack_check_old_cflags $SSP_FLAGS",
Chris@40: 		AC_MSG_RESULT([no])
Chris@40: 			CFLAGS="$xiph_stack_check_old_cflags"
Chris@40: 		)
Chris@40: 	AC_LANG_POP([C++])
Chris@40: ])# XIPH_GXX_STACK_PROTECTOR