Re: Fix handling of calls wrt EH

[Jan Hubicka <jh at suse dot cz>]

> > On Fri, May 13, 2005 at 05:26:54AM +0200, Jan Hubicka wrote:
> > > +   /* ??? For the benefit of calls.c, converting all this to rtl,
> > > +      we need to record the call expression, not just the outer
> > > +      modify statement.  */
> > > +   if ((TREE_CODE (t) == MODIFY_EXPR
> > > +        || TREE_CODE (t) == RETURN_EXPR)
> > > +       && (t = get_call_expr_in (t)))
> > > +     add_stmt_to_eh_region_fn (ifun, t, num);
> > 
> > If we're going to do this, I think we should rearrange add_stmt_eh_region
> > and record_stmt_eh_region (and their callers) such that we only do this in
> > one place.
> > 
> > And did you really need to check RETURN_EXPR?  We're not testing for that
> > in lower_eh_constructs_1.  Either your test is unnecessary or we've got a
> > latent bug.
> 
> I guess it is not neccesary, I just copied what the old code did without
> much thinking abou it ;(
> Does the attached patch seem to make more sense (I just started testing
> it)
> I guess I can also add verify_flow_info check that call_expr is in sync
> (I have few extra EH checking bits so I will push this out together if
> we decide to walk this way)

Doh, forgot one extra RETURN_EXPR check few lines down.  Fixed thus and
bootstrapped/regtested i686-pc-gnu-linux.

2005-05-13  Jan Hubicka  <jh@suse.cz>
	* tree-cfg.c (execute_warn_function_return): Break out noreturn
	warning too..
	(execute_warn_function_noreturn): ... here.
	(pass_warn_function_noreturn): New pass.
	* tree-pass.h (pass_warn_function_noreturn): Declare
	* tree-optimize.c (init_tree_optimization_passes): Move return
	warnings early and add noreturn warnings at place of previous
	return warnings.

Index: tree-eh.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/tree-eh.c,v
retrieving revision 2.35
diff -c -3 -p -r2.35 tree-eh.c
*** tree-eh.c	12 May 2005 19:29:21 -0000	2.35
--- tree-eh.c	13 May 2005 20:06:31 -0000
*************** struct_ptr_hash (const void *a)
*** 84,102 ****
  static void
  record_stmt_eh_region (struct eh_region *region, tree t)
  {
-   struct throw_stmt_node *n;
-   void **slot;
- 
    if (!region)
      return;
  
!   n = ggc_alloc (sizeof (*n));
!   n->stmt = t;
!   n->region_nr = get_eh_region_number (region);
! 
!   slot = htab_find_slot (get_eh_throw_stmt_table (cfun), n, INSERT);
!   gcc_assert (!*slot);
!   *slot = n;
  }
  
  void
--- 84,93 ----
  static void
  record_stmt_eh_region (struct eh_region *region, tree t)
  {
    if (!region)
      return;
  
!   add_stmt_to_eh_region (t, get_eh_region_number (region));
  }
  
  void
*************** add_stmt_to_eh_region_fn (struct functio
*** 120,125 ****
--- 111,122 ----
    slot = htab_find_slot (get_eh_throw_stmt_table (ifun), n, INSERT);
    gcc_assert (!*slot);
    *slot = n;
+   /* ??? For the benefit of calls.c, converting all this to rtl,
+      we need to record the call expression, not just the outer
+      modify statement.  */
+   if (TREE_CODE (t) == MODIFY_EXPR
+       && (t = get_call_expr_in (t)))
+     add_stmt_to_eh_region_fn (ifun, t, num);
  }
  
  void
*************** remove_stmt_from_eh_region_fn (struct fu
*** 143,148 ****
--- 140,151 ----
    if (slot)
      {
        htab_clear_slot (get_eh_throw_stmt_table (ifun), slot);
+       /* ??? For the benefit of calls.c, converting all this to rtl,
+ 	 we need to record the call expression, not just the outer
+ 	 modify statement.  */
+       if (TREE_CODE (t) == MODIFY_EXPR
+ 	  && (t = get_call_expr_in (t)))
+ 	remove_stmt_from_eh_region_fn (ifun, t);
        return true;
      }
    else
*************** lower_eh_constructs_1 (struct leh_state 
*** 1618,1634 ****
        /* Look for things that can throw exceptions, and record them.  */
        if (state->cur_region && tree_could_throw_p (t))
  	{
- 	  tree op;
- 
  	  record_stmt_eh_region (state->cur_region, t);
  	  note_eh_region_may_contain_throw (state->cur_region);
- 
- 	  /* ??? For the benefit of calls.c, converting all this to rtl,
- 	     we need to record the call expression, not just the outer
- 	     modify statement.  */
- 	  op = get_call_expr_in (t);
- 	  if (op)
- 	    record_stmt_eh_region (state->cur_region, op);
  	}
        break;
  
--- 1621,1628 ----
*************** lower_eh_constructs (void)
*** 1689,1697 ****
    tree *tp = &DECL_SAVED_TREE (current_function_decl);
  
    finally_tree = htab_create (31, struct_ptr_hash, struct_ptr_eq, free);
-   set_eh_throw_stmt_table (cfun, htab_create_ggc (31, struct_ptr_hash,
- 						  struct_ptr_eq,
- 						  ggc_free));
  
    collect_finally_tree (*tp, NULL);
  
--- 1683,1688 ----