1dnl Copyright (C) 2013 Xiph.org Foundation 2dnl 3dnl Redistribution and use in source and binary forms, with or without 4dnl modification, are permitted provided that the following conditions 5dnl are met: 6dnl 7dnl - Redistributions of source code must retain the above copyright 8dnl notice, this list of conditions and the following disclaimer. 9dnl 10dnl - Redistributions in binary form must reproduce the above copyright 11dnl notice, this list of conditions and the following disclaimer in the 12dnl documentation and/or other materials provided with the distribution. 13dnl 14dnl - Neither the name of the Xiph.org Foundation nor the names of its 15dnl contributors may be used to endorse or promote products derived from 16dnl this software without specific prior written permission. 17dnl 18dnl THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 19dnl ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 20dnl LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 21dnl A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR 22dnl CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 23dnl EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 24dnl PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 25dnl PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 26dnl LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 27dnl NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 28dnl SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29 30dnl Want to know of GCC stack protector works, botfor the C and for the C++ 31dnl compiler. 32dnl 33dnl Just checking if the compiler accepts the required CFLAGSs is not enough 34dnl because we have seen at least one instance where this check was 35dnl in-sufficient. 36dnl 37dnl Instead, try to compile and link a test program with the stack protector 38dnl flags. If that works, we use it. 39 40AC_DEFUN([XIPH_GCC_STACK_PROTECTOR], 41[AC_LANG_ASSERT(C) 42 AC_MSG_CHECKING([if $CC supports stack smash protection]) 43 xiph_stack_check_old_cflags="$CFLAGS" 44 SSP_FLAGS="-fstack-protector --param ssp-buffer-size=4" 45 CFLAGS=$SSP_FLAGS 46 AC_TRY_LINK([ 47 #include <stdio.h> 48 ], 49 [puts("Hello, World!"); return 0;], 50 AC_MSG_RESULT([yes]) 51 CFLAGS="$xiph_stack_check_old_cflags $SSP_FLAGS", 52 AC_MSG_RESULT([no]) 53 CFLAGS="$xiph_stack_check_old_cflags" 54 ) 55])# XIPH_GCC_STACK_PROTECTOR 56 57AC_DEFUN([XIPH_GXX_STACK_PROTECTOR], 58[AC_LANG_PUSH([C++]) 59 AC_MSG_CHECKING([if $CXX supports stack smash protection]) 60 xiph_stack_check_old_cflags="$CFLAGS" 61 SSP_FLAGS="-fstack-protector --param ssp-buffer-size=4" 62 CFLAGS=$SSP_FLAGS 63 AC_TRY_LINK([ 64 #include <cstdio> 65 ], 66 [puts("Hello, World!"); return 0;], 67 AC_MSG_RESULT([yes]) 68 CFLAGS="$xiph_stack_check_old_cflags $SSP_FLAGS", 69 AC_MSG_RESULT([no]) 70 CFLAGS="$xiph_stack_check_old_cflags" 71 ) 72 AC_LANG_POP([C++]) 73])# XIPH_GXX_STACK_PROTECTOR 74