code instrumentation in the tree structure

[Björn Skoglund <skoglund at lysator dot liu dot se>]

Hi everyone

I don't know if this is a development-list issue but I thought I'd try. 
I'm writing a code instrumentation tool using the GEM
plugin-system (http://www.ecsl.cs.sunysb.edu/gem/) as a part of my
thesis project. I got it working in gcc-3.4 with a little help from the
GEM maintainer but I have realized I need to move to gcc-4 to get access
to the control-flow manipulation tools. Now my problem is that my code
which inserted function call statements does not work under the gcc-4
environment. the EXPR_STMT-symbol is gone for example. which makes the line

> t_new_stmt = build_nt(EXPR_STMT, t_call);

cause compilation errors. Now, has the notion of statements been removed
in gcc-4, and in that case what has replaced it? I am quite confused at
the moment so if something doesn't make sense I'd be very happy with any
kind of explanation that makes me understand again. The following piece
of code is what I'm working with at the moment. It compiles but doesn't
really cause anything to happen when run.

> void ci_insert_call(tree t_func, const char* func_name, tree args) {
>  tree t_func_decl;
>  tree t_body;
>  tree t_first_stmt;
>
>  tree t_call;
>  tree t_new_stmt;
>
>
>  t_body=DECL_SAVED_TREE(t_func); // COMPOUND_STMT
> /*   t_first_stmt = COMPOUND_BODY(t_body);  */
>
>  gem_find_symtab(&t_func_decl, func_name);
>  t_call=build_function_call(t_func_decl, args);
>  t_new_stmt = build_nt(CALL_EXPR, t_call);
> /*   TREE_CHAIN(t_new_stmt)=TREE_CHAIN(t_first_stmt); */
> /*   TREE_CHAIN(t_first_stmt)=t_new_stmt; */
>  tree_stmt_iterator itor;
>  itor = tsi_start(t_body);
>  tsi_link_before(&itor, t_new_stmt, TSI_SAME_STMT);
> }


Cheers!
/Björn Skoglund