[Bug middle-end/29478] [4.2 Regression] optmization generates warning for casts

["amylaar at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #7 from amylaar at gcc dot gnu dot org  2006-10-23 17:30 -------
(In reply to comment #6)
> A regression hunt identified the following patch:
> 
>     http://gcc.gnu.org/viewcvs?view=rev&rev=116424
> 
>     r116424 | amylaar | 2006-08-25 18:51:57 +0000 (Fri, 25 Aug 2006)
> 

When I modify the testcase to have the function defintion after the use:

struct block;

static int remove_out_of_scope_renamings ();

int
ada_lookup_symbol_list (const struct block *block0)
{
  return remove_out_of_scope_renamings ((struct block *) block0);
}

static int
remove_out_of_scope_renamings (current_block)
  struct block *current_block;
{
  return 1;
}

I still see that the cast has been stripped at the point where
c_convert_parm_for_inlining is called:

(gdb) call debug_tree(value)
 <parm_decl 0xb593c000 block0
    type <pointer_type 0xb59315c0
        type <record_type 0xb5931564 block readonly VOID
...

OTOH, if I further change the passed parameter to a plain 0, value contains an
unadorned integer constant.   

(gdb) call debug_tree(value)
 <integer_cst 0xb58aa978 type <integer_type 0xb58bb284 int> constant invariant
0>

I think it is wrong that we are optimizing the expression before converting
it to the required type.
Moreover, why is it right to drop NOP_EXPRESSIONS there?  If for some reason
the compiler finds it needs to put the initializer in a temporary variable,
and uses the type of the value for that variable, we'll get an alias set
problem.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29478