| # =========================================================================== |
| # Modified from https://www.gnu.org/software/autoconf-archive/ax_add_fortify_source.html |
| # =========================================================================== |
| # |
| # SYNOPSIS |
| # |
| # AX_ADD_FORTIFY_SOURCE |
| # |
| # DESCRIPTION |
| # |
| # Check whether -D_FORTIFY_SOURCE=2 can be added to CFLAGS without macro |
| # redefinition warnings. Some distributions (such as Gentoo Linux) enable |
| # _FORTIFY_SOURCE globally in their compilers, leading to unnecessary |
| # warnings in the form of |
| # |
| # <command-line>:0:0: error: "_FORTIFY_SOURCE" redefined [-Werror] |
| # <built-in>: note: this is the location of the previous definition |
| # |
| # which is a problem if -Werror is enabled. This macro checks whether |
| # _FORTIFY_SOURCE is already defined, and if not, adds -D_FORTIFY_SOURCE=2 |
| # to CFLAGS. |
| # |
| # LICENSE |
| # |
| # Copyright (c) 2017 David Seifert <soap@gentoo.org> |
| # |
| # Copying and distribution of this file, with or without modification, are |
| # permitted in any medium without royalty provided the copyright notice |
| # and this notice are preserved. This file is offered as-is, without any |
| # warranty. |
| |
| #serial 1 |
| |
| AC_DEFUN([AX_ADD_FORTIFY_SOURCE],[ |
| AC_MSG_CHECKING([whether to add -D_FORTIFY_SOURCE=2 to CFLAGS]) |
| AC_LINK_IFELSE([ |
| AC_LANG_SOURCE( |
| [[ |
| int main() { |
| #ifndef _FORTIFY_SOURCE |
| return 0; |
| #else |
| this_is_an_error; |
| #endif |
| } |
| ]] |
| )], [ |
| AC_MSG_RESULT([yes]) |
| CFLAGS="$CFLAGS -D_FORTIFY_SOURCE=2" |
| ], [ |
| AC_MSG_RESULT([no]) |
| ]) |
| ]) |
