traverse the gimple tree

[sean yang]

Thanks for reply.
What I am trying to do is something like counting the times of a particular 
function call, i.e.,  whenever there is a CALL_EXPR in the tree, I want to 
look at the id to see if that is the function I want to count during 
runtime.  If the id is the function name I want to count, I insert a counter 
instruction.

It seems that I can mimic the code of dump_generic_node() (which is called 
by dump_function() ) to do my instrumentation. However, here I have two 
questions:
(1) dump_generic_node() is definietly an overkill to my problem because it 
takes care of all the NODE type, even the node I am not interested in, such 
as TYPEs, DECLs. Based on what I want to do (described above), is there an 
easy and cleaner way than the following pseudo code? i.e, is there a way 
that I don't need to go through all the GIMPLE grammar situation (because 
this is error-prone)?

pass_function_instrument(){
   instrument( &DECL_SAVED_TREE (current_function_decl) );
}

instrument (tree *tp){

  switch (TREE_NODE(*tp) ){
      case CALL_EXPR:
           insert_counter_instruction(tp);
      case COND_EXPR:
           //COND_EXPR_COND (tp) can't contain stmts any more
           instrument (COND_EXPR_THEN (tp));
           instrument (COND_EXPR_ELSE (tp));;
      case BIND_EXPR:
           //BIND_EXPR_VARS (tp) can't contain stmts any more
          instrument(BIND_EXPR_BODY (tp) );
       case STATEMENT_LIST:
           i = tsi_start();
           which (!tsi_end_p (i))
                {
                   instrument (tsi_stmt (i));
                   tsi_next(&i);
                }
        case: ...
  }
}

(2) It seem to me that TREE_LIST and TREE_VEC node is not reachable from 
DECL_SAVED_TREE node according to GIMPLE grammar. By I did see case taking 
care of them in dump_generic_node().
Can someone explain TREE_LIST and TREE_VEC to me?

Thanks,
Sean


>From: Zdenek Dvorak <rakdver@atrey.karlin.mff.cuni.cz>
>To: sean yang <seanatpurdue@hotmail.com>
>CC: gcc@gcc.gnu.org
>Subject: Re: traverse the gimple tree
>Date: Tue, 11 Apr 2006 13:56:48 +0200
>
>Hello,
>
> > I want to write a pass to walk the gimple tree and add some 
>intrumentation
> > code. I read the chapter 9 of "GCC Internals" document, and it seems not 
>to
> > describe the Macros to do so.
> >
> > Can I get some information about this? Specifically, if someone can show 
>me
> > which .h file I should look at to find the Macros, that would be great. 
>Or,
> > Is there any other pass do the similar thing(traverse the gimple tree) 
>that
> > I can read (--I did not find)?
>
>depending on what you need, you may use walk_tree and/or combination of
>special-handling for structured statements and tsi_ iterators, at that
>point.  See e.g. pass_lower_cf.
>
>Zdenek
>
> > ------------------------------------------------
> > //in gcc.4.0.2, tree-optimize.c
> >    323 void
> >    324 init_tree_optimization_passes (void)
> >    325 {
> >    326   struct tree_opt_pass **p;
> >    327
> >    328 #define NEXT_PASS(PASS)  (p = next_pass_1 (p, &PASS))
> >    329
> >    330   p = &all_passes;
> >    331   NEXT_PASS (pass_gimple);
> >    332
> >    333   NEXT_PASS (MYPASS_code_instrument); //this is what I want to do
> >    334   //the reason I want to add the pass here is: both C/C++(any 
>other
> > front end, later) can use this;
> >    335   NEXT_PASS (pass_remove_useless_stmts);
> >    336   NEXT_PASS (pass_mudflap_1);
> >    337   NEXT_PASS (pass_lower_cf);
> >    338   NEXT_PASS (pass_lower_eh);
> >    339   NEXT_PASS (pass_build_cfg);
> > ......
> > }
> > --------------------------------------------------------
> >
> > _________________________________________________________________
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