On Fri, Nov 03, 2023 at 06:51:16PM -0400, Marek Polacek wrote:
> + if (flag_hardened)
> + {
> + if (!fortify_seen_p && optimize > 0)
> + {
> + if (TARGET_GLIBC_MAJOR == 2 && TARGET_GLIBC_MINOR >= 35)
> + cpp_define (parse_in, "_FORTIFY_SOURCE=3");
> + else
> + cpp_define (parse_in, "_FORTIFY_SOURCE=2");
> + }
I don't like the above in generic code, the fact that gcc was configured
against glibc target headers doesn't mean it is targetting glibc.
E.g. for most *-linux* targets, config/linux.opt provides the
-mbionic/-mglibc/-muclibc/-mmusl options.
One ugly way around would be to do
#ifdef OPTION_GLIBC
if (OPTION_GLIBC && TARGET_GLIBC_MAJOR == 2 && TARGET_GLIBC_MINOR >= 35)
cpp_define (parse_in, "_FORTIFY_SOURCE=3");
else
#endif
cpp_define (parse_in, "_FORTIFY_SOURCE=2");
(assuming OPTION_GLIBC at that point is already computed); a cleaner way
would be to introduce a target hook for that, say
fortify_source_default_level or something similar, where the default hook
would return 2 and next to linux_libc_has_function one would override it
for OPTION_GLIBC && TARGET_GLIBC_MAJOR == 2 && TARGET_GLIBC_MINOR >= 35
to 3. That way, in the future other targets (say *BSD) can choose to do
something similar more easily.
The rest LGTM.
Jakub
