Hi,
the testcase would be wonderful - those bugs are hard to catch. I fixed some
issues
recently, so you may try recent snapshot if you didn't.
You may try -fno-devirtualize to see if the bug goes away (likely it will) and
you
may try to look in -fdump-tree-all -fdump-ipa-all dumps where cxa_pure_virtual
call
appears in the program and send me some context.
Honza
> Hi Jan,
>
> I hope to report a bug soon, but in the meantime I wanted to let
> you know that for the last month or so, the 4.9 branch has (I think)
> a bug at O3, where my program gets:
>
> pure virtual method called
> terminate called without an active exception
> Aborted
>
> 4.8 works fine.
>
> I am guessing this is related to your devirt work. I haven't
> been able to produce a reduce testcase yet (sorry!), but here is
> some code that illustrates the C++ type for the object whose virtual
> table is (?) messed up. (Note: this code compiles but does NOT
> crash.)
>
> Again, sorry for not having a testcase. I'll make one soon.
> Hopefully it is helpful to know that bugs still exist.
>
> -BenRI
>
> #include <vector>
>
> class Object
> {
> virtual Object* clone() const =0;
> };
>
> template <typename T>
> class Box: public Object, public T
> {
> public:
> Box<T>* clone() const {return new Box<T>(*this);}
> };
>
> template <typename T>
> using Vector = Box<std::vector<T>>;
>
> int main()
> {
> Vector<int> v;
> v.clone();
> }
>
> -BenRI
>
> P.S. The bug exists in debian gcc snapshots taken on 2014-02-12 and
> 2014-01-22, Linux AMD64.
