[Bug sanitizer/70147] [6 Regression] testcase from hana testsuite gets miscompiled with -fsanitize=undefined

[bernd.edlinger at hotmail dot de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70147

--- Comment #17 from Bernd Edlinger <bernd.edlinger at hotmail dot de> ---
(In reply to Jakub Jelinek from comment #16)
> Created attachment 37965 [details]
> gcc6-pr70147-2.patch
> 

this patch looks good to me.
Thanks.

> As the compromise I meant this instead (incremental patch).
> Though, in that case the -flifetime-dse=2 clobbers are also wrong in the
> subobject ctors, because they should not overlap the vtable pointers of the
> virtual bases if we rely on them from the caller, otherwise when those are
> inlined could be DSEd, even when we actually rely on them.

However that sounds more or less like a P1-BUG !

If the virtual base has already initialized the base object,
maybe it has put it into a linked list, or so all that code will
silently be removed again, and the list would be left in an
inconsistent state.

Do you see a way, how to conditionalize the clobber on the in_charge?


Bernd.