Getting a virtual functions VT lookup index

[Brendon Costa <bcosta at avdat dot com dot au>]

Hi all,

How can I find a FUNCTION_DECL node from a CALL_EXPR node for virtual
function calls?

Note: I am not after the node for the function that will be executed
at runtime as I know this is not possible to determine in most
situations.


Thanks for any help in advance,
Brendon.



-----------------------
I have tried the following:

When I encounter a CALL_EXPR for a virtual function call, I can get
the index for the virtual function table from the OBJ_TYPE_REF object
operand: 2 is an INTEGER_CST that seems to have a different index for
the various virtual functions.

However I need to find the FUNCTION_DECL node that is associated with
a particular type with the given virtual function table index.

For example if I have a index value of: 1 that I have obtained from
the OBJ_TYPE_REF node operand 2 I can also get the METHOD_TYPE node
and thus get the RECORD_TYPE node for the object.

How can I find the FUNCTION_DECL node given the virtual table index of
the function and the classes RECORD_TYPE node?

* I have tried using class.c: get_vcall_index() but it seems to return
negative integers.

* I have also looked in the TYPE_BINFO with the BINFO_VIRTUALS for the
BV_CALL_INDEX but that is NULL.

* I have also tried using CLASSTYPE_VCALL_INDICES and all these have
failed to give me a value that seems correct.