[PATCH][C++] Fix PR38334, TBAA issues with vtbl loads

Mark Mitchell mark@codesourcery.com
Tue Dec 2 21:47:00 GMT 2008


Richard Guenther wrote:

> Sure.  The problem is we only know after inlining and some non-trivial
> optimization (and at this point nothing distinguishes the access from
> other pointer arithmetic and accesses).  I can disable the spurious
> warning easily if you tell me that if the vtbl load is not "dead" then
> the referenced object does contain such a pointer (and we know that
> by means of recording a proper alias relationship).

Any C++ program that tries to apply a virtual pointer-to-function-member
to a object whose dynamic type is not dynamic has undefined behavior.
Is that what you're asking?

-- 
Mark Mitchell
CodeSourcery
mark@codesourcery.com
(650) 331-3385 x713



More information about the Gcc-patches mailing list