llvm dev - May 2017 - Get function pointers from VTable

Hello,

I am currently in the process of retrieving the virtual function pointers
from the vtable though writing a pass and examining the IR.

I know that the vtable is represented with names beginning in "_ZTV"
and
i32 (...)** represents the type of the vptr fields.

Where I am stuck and need help with is in getting the vptr addresses from
the array being accessed by the getelementptr:

 store i32 (...)** bitcast (i8** getelementptr inbounds ([5 x i8*], [5 x
i8*]* @_ZTV9Rectangle, i32 0, i32 2) to i32 (...)**), i32 (...)*** %5,
align 8


I am able to get this operand from the store instruction op[0] and know
that it is a ConstantExpr, how do i access the individual indices. I know
that I need the info from index 2 till 5 in this case.

Can anyone help with getting the vptr address from within the table?

Thanks,

Dami
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
<http://lists.llvm.org/pipermail/llvm-dev/attachments/20170525/e3ef53b1/attachment.html>