+dnl Compiler hardening flags
+dnl No -fstack-protector-all because it doesn't work on all platforms or architectures.
+
+AC_ARG_ENABLE([hardening], AS_HELP_STRING([--disable-hardening], [disable compiler and linker hardening flags]))
+AS_IF([test "x$enable_hardening" != "xno"],
+ [CPPFLAGS="$CPPFLAGS -Wall -W -pedantic"
+ AX_CHECK_COMPILE_FLAG([-DFORTIFY_SOURCE=2], [CPPFLAGS="$CPPFLAGS -DFORITFY_SOURCE=2"])
+ AX_CHECK_COMPILE_FLAG([-fwrapv], [CPPFLAGS="$CPPFLAGS -fwrapv"],
+ [AX_CHECK_COMPILE_FLAG([-fno-strict-overflow], [CPPFLAGS="$CPPFLAGS -fno-strict-overflow"])]
+ )
+ case $host_os in
+ *mingw*)
+ AX_CHECK_LINK_FLAG([-Wl,--dynamicbase], [LDFLAGS="$LDFLAGS -Wl,--dynamicbase"])
+ AX_CHECK_LINK_FLAG([-Wl,--nxcompat], [LDFLAGS="$LDFLAGS -Wl,--nxcompat"])
+ ;;
+ *)
+ AX_CHECK_COMPILE_FLAG([-fPIC], [CPPFLAGS="$CPPFLAGS -fPIC"])
+ ;;
+ esac
+ AX_CHECK_LINK_FLAG([-Wl,-z,relro], [LDFLAGS="$LDFLAGS -Wl,-z,relro"])
+ AX_CHECK_LINK_FLAG([-Wl,-z,now], [LDFLAGS="$LDFLAGS -Wl,-z,now"])
+ AX_CHECK_COMPILE_FLAG([-Wextra -pedantic -Wreturn-type -Wold-style-definition -Wmissing-declarations -Wmissing-prototypes -Wstrict-prototypes -Wredundant-decls -Wshadow -Wbad-function-cast -Wwrite-strings -fdiagnostics-show-option -fstrict-aliasing -Wmissing-noreturn], [CPPFLAGS="$CPPFLAGS -Wextra -pedantic -Wreturn-type -Wold-style-definition -Wmissing-declarations -Wmissing-prototypes -Wstrict-prototypes -Wredundant-decls -Wshadow -Wbad-function-cast -Wwrite-strings -fdiagnostics-show-option -fstrict-aliasing -Wmissing-noreturn"])
+ ]
+);