[Generic] CALL_EXPR tree code with object ref

[charfi asma <charfiasma at yahoo dot fr>]

Hello,

I have a class (represented as RECORD_TYPE), and a method of this class 
(TYPE_METHODS(class_type) = operation).

operation is a FUNCTION_DECL:  tree operation = build_decl(BUILTINS_LOCATION, 
FUNCTION_DECL, get_identifier("MyOperation"), operation_type);

I created a variable named "x"  of type class_type:  tree object = 
build_decl(BUILTINS_LOCATION, VAR_DECL, get_identifier("x"), class_type);

I want to use call_expr tree code to call my_method on x (the equivalent of : 
x.My_Operation() ).

In this last  post http://gcc.gnu.org/ml/gcc-help/2010-10/msg00388.html , Ian 
suggest this:

"... To call a method, you have to construct an expression which refers to
the method.  In C++, for example, this would mean an expression which
loads a function pointer from a vtable "

but I can not do it :(

1. I tried to follow the cp front end, but I get errors related to GTY.

I tried to include class.c, call.c or method.c to reuse the defined functions 
like build_this_parm to add the param "this" to the call_exp, because when I 
look at the gimple generated from the c++ call I find that I have to add "this" 
to the 

function decl and add it also to the call_expr (&c)

main ()
gimple_bind <
  struct MyClass x;
  gimple_call <MyOperation, NULL, &x>
>

void MyClass::MyOperation() (struct MyClass * const this)
gimple_bind <
  GIMPLE_NOP
>

2. I tried also to use the tree code defined in tree.def like COMPONENT_REF (but 

it is only used for FIELD_DECL and not TYPE_METHOD of a RECORD_TYPE)

I followed the sfe fe when It calls a function, but it uses a pointer to a 
function and not a direct call to the function
I added this : 

tree __struct_access_1 = build3(COMPONENT_REF, class_type,operation, x, 
NULL_TREE); // exp pour l'objet
tree __call_expr = build_call_expr(__struct_access_1, 0);
append_to_statement_list(__call_expr, &main_stmts);

but I get error when gimplifying the main function
(gdb) n
148      gimplify_function_tree(main_fn_decl);
(gdb) n

Program received signal SIGSEGV, Segmentation fault.
size_binop_loc (loc=0, code=EXACT_DIV_EXPR, arg0=0x0, arg1=0xb743d680)
    at ../../gcc-dev/gcc/fold-const.c:1414
1414      tree type = TREE_TYPE (arg0);

3. I tried to use OBJ_TYPE_REF tree code defined in tree.def to get the ref to 
an object but I can not find a build_obj_type_ref in the tree.c  to use it (just 

like build_call_exp ).

If so is familiar with the cp front end or any object oriented fe, I will be 
very thankfull if  he help me on doing this


thanks a lot

Asma