Getting type used in THROW_EXPR

[Richard Guenther]

On 10/14/06, Brendon Costa <brendon@christian.net> wrote:
> Hi all,
>
> I have yet another question that has arisen as i have started testing my
> code. Basically I am trying to get the type that is being used in
> throwing an exception.
>
>
> Is there a simple macro i can use to get the type of an exception from a
> THROW_EXPR? I think this is a matter of getting the TREE_TYPE for the
> value passed into the function: except.c: build_throw(tree exp)

If you look at cp/cp-tree.def you will see

/* A throw expression.  operand 0 is the expression, if there was one,
   else it is NULL_TREE.  */
DEFTREECODE (THROW_EXPR, "throw_expr", tcc_expression, 1)

which means that TREE_OPERAND (t, 0) is the expression thrown.  Based
on whether that is a reference already or not, you need to create a
reference by your own using build1 (ADDR_EXPR, ...) with a properly
constructed reference type (I guess there's some helper for that in the
C++ frontend).

Richard.