How can i get a ref from a this pointer ?

[Richard Buchmann <Richard dot Buchmann at lip6 dot fr>]

Hello,

I'm looking for a simple way to get something like a COMPONENT_REF tree node
from an expression tree node.

CALL_EXPR node has 2 operands : (see tree.def)
Operand 0 is the function.
Operand 1 is the argument list, a list of expressions made out of a chain of TREE_LIST nodes.

In some cases, the operand 0 is an expression for 'self' parameter. This
expression is an arithmetic expression using two operands. Their both type is a
pointer.

How can i get the COMPONENT_REF tree node from this expression ?

Example :

struct bar {
  bar& operator = (int)
  {
    return *this;
  }
};

struct foo {
  bar a;
  bar b;
  void test () {
    b = 3;
  };
};


In this example, there is a CALL_EXPR node for "b = 3" expression.
The first operand is a PLUS_EXPR node.
The second operand is a integer node.

The PLUS_EXPR node has 2 operands : the first is a NOP_EXPR node (this
pointer...) and the second one is an integer node (the offset).
I would like to get a COMPONENT_REF node to know what FIELD is used : a or b.

I need this information from the intermediate representation used by the C and
C++ front ends before to reach another pass.

Thank you.
Best Regards.

Richard Buchmann