Re: Tree

[Jonathan Wakely <jwakely dot gcc at gmail dot com>]

On 4 July 2011 15:28, konica sarker wrote:
> "A tree is a pointer type, but the object to which it points may be of
> a variety of types"
>
> suppose i have a tree t;
> can you help me, how to identify the object type of the tree?

>From http://gcc.gnu.org/onlinedocs/gccint/Tree-overview.html

"You can tell what kind of node a particular tree is by using the
TREE_CODE macro."

> what does the function TREE_TYPE() do?

>From http://gcc.gnu.org/onlinedocs/gccint/Macros-and-Functions.html

"Many trees store the type of an expression or declaration in this field."

And from gcc/tree.h:

/* In all nodes that are expressions, this is the data type of the expression.
   In POINTER_TYPE nodes, this is the type that the pointer points to.
   In ARRAY_TYPE nodes, this is the type of the elements.
   In VECTOR_TYPE nodes, this is the type of the elements.  */
#define TREE_TYPE(NODE) __extension__ \
(*({__typeof (NODE) const __t = CONTAINS_STRUCT_CHECK (NODE, TS_TYPED); \
    &__t->typed.type; }))