kc3-lang/libressl/m4/ax_add_fortify_source.m4

• Show log

  Commit

• Hash : 56202472
  Author :
  Date : 2020-08-20T02:18:39
  

  Add a compile-time check for FORTIFY_SOURCE support
  
  This is broken on some platforms, so pull in the conditional macro from
  the latest version of autoconf-archive to test for working support.
  

Download

• m4/ax_add_fortify_source.m4

• # ===========================================================================
  #  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 CPPFLAGS without macro
  #   redefinition warnings, other cpp warnings or linker. 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 CPPFLAGS.
  #
  #   Newer mingw-w64 msys2 package comes with a bug in
  #   headers-git-7.0.0.5546.d200317d-1. It broke -D_FORTIFY_SOURCE support,
  #   and would need -lssp or -fstack-protector.  See
  #   https://github.com/msys2/MINGW-packages/issues/5803. Try to actually
  #   link it.
  #
  # LICENSE
  #
  #   Copyright (c) 2017 David Seifert <soap@gentoo.org>
  #   Copyright (c) 2019 Reini Urban <rurban@cpan.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 4
  
  AC_DEFUN([AX_ADD_FORTIFY_SOURCE],[
      ac_save_cflags=$CFLAGS
      ac_cwerror_flag=yes
      AX_CHECK_COMPILE_FLAG([-Werror],[CFLAGS="$CFLAGS -Werror"])
      AC_MSG_CHECKING([whether to add -D_FORTIFY_SOURCE=2 to CPPFLAGS])
      AC_LINK_IFELSE([
          AC_LANG_PROGRAM([],
              [[
                  #ifndef _FORTIFY_SOURCE
                      return 0;
                  #else
                      this_is_an_error;
                  #endif
              ]]
          )],
          AC_LINK_IFELSE([
              AC_LANG_SOURCE([[
                  #define _FORTIFY_SOURCE 2
                  #include <string.h>
                  int main() {
                      char *s = " ";
                      strcpy(s, "x");
                      return strlen(s)-1;
                  }
                ]]
              )],
              [
                AC_MSG_RESULT([yes])
                CFLAGS=$ac_save_cflags
                CPPFLAGS="$CPPFLAGS -D_FORTIFY_SOURCE=2"
              ], [
                AC_MSG_RESULT([no])
                CFLAGS=$ac_save_cflags
              ],
          ),
          [
            AC_MSG_RESULT([no])
            CFLAGS=$ac_save_cflags
          ])
  ])
  

Download