https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63888
--- Comment #34 from Kostya Serebryany <kcc at gcc dot gnu.org> ---
(In reply to Jakub Jelinek from comment #31)
> Any progress on this?
>
> If not, I'm considering doing:
> --- libsanitizer/asan/asan_globals.cc.jj 2014-11-14 00:10:34.000000000
> +0100
> +++ libsanitizer/asan/asan_globals.cc 2015-02-20 11:43:33.179177767 +0100
> @@ -148,7 +148,9 @@ static void RegisterGlobal(const Global
> CHECK(AddrIsInMem(g->beg));
> CHECK(AddrIsAlignedByGranularity(g->beg));
> CHECK(AddrIsAlignedByGranularity(g->size_with_redzone));
> - if (flags()->detect_odr_violation) {
> + // This "ODR violation" detection is fundamentally incompatible with
> + // how GCC registers globals. Disable as useless until rewritten
> upstream.
> + if (0 && flags()->detect_odr_violation) {
> // Try detecting ODR (One Definition Rule) violation, i.e. the situation
> // where two globals with the same name are defined in different
> modules.
> if (__asan_region_is_poisoned(g->beg, g->size_with_redzone)) {
> for now.
Sorry, this got pushed back in the queue...
Sure, feel free to commit something like this.
Slightly better place is at the definition of detect_odr_violation -- change
the default to 0 and mark the change with some visible markers.
Obviously we'll need to do a proper fix upstream before the next merge.
Frankly, I am not at all motivated to do any significant surgery in the llvm
compiler instrumentation because for me everything works fine.
We can extend the Global struct to have a boolean (bit?) that says whether we
are checking for ODRs (as you suggested above). This will be a new ABI break.
Not a big deal, of course.
I wonder if we can somehow else detect that the module is compiled with GCC and
disable the checking in that case?
