[Bug fortran/32732] [Bind C] Character scalars are passed as arrays

[Christopher D. Rickett]

hi Steve,

i am able to see similar output from debug_tree on my x86 linux box, so 
that's a starting point.  i've modified the code in generate_local_decl to 
use some of the code from my old set_tree_decl_type_code and it seems to 
eliminate the references to array_type in the debug_tree output.  i've 
regtested the changes on x86/linux with no new failures, but i have not 
done a full bootstrap.

could you add the following three lines after the line you mentioned from 
generate_local_decl:

 	  DECL_BY_REFERENCE (sym->backend_decl) = 0;
 	  DECL_ARG_TYPE (sym->backend_decl) = TREE_TYPE 
(sym->backend_decl);
 	  DECL_MODE (sym->backend_decl) =
 	    TYPE_MODE (TREE_TYPE (sym->backend_decl));

would you mind trying this out and letting me know if it fixes the 
problem.  as i mentioned, it seems to remove any references to an 
array_type from the debug_tree output on my x86 linux box.

thanks.
Chris



On Thu, 26 Jul 2007, Steve Ellcey wrote:

>>> I will look more into the char issue and see if I can get some more data on what is happening.
>>>
>> Thanks and good look. These are all "abort()" failures and no
>> segmentation faults, are they?
>>
>> Tobias
>
> So I am hitting the new code in generate_local_decl where we do:
>
> 	TREE_TYPE (sym->backend_decl) = unsigned_char_type_node;
>
> But I don't think this type change is enough to fix the problem.  If I
> do a debug_tree of sym->backend_decl after this statement I get:
>
> <parm_decl 7d6cc270 my_char
>    type <integer_type 7d6d8150 char public unsigned string-flag QI
>        size <integer_cst 7d6c5208 constant invariant 8>
>        unit size <integer_cst 7d6c5230 constant invariant 1>
>        align 8 symtab 0 alias set -1 canonical type 7d6d8150 precision 8 min <integer_cst 7d6c5258 0> max <integer_cst 7d6c5280 255>
>        pointer_to_this <pointer_type 7d6e0690>>
>    readonly used QI file x.f90 line 6 size <integer_cst 7d6c5208 8> unit size <integer_cst 7d6c5230 1>
>    align 8 context <function_decl 7d76dc30 param_test> initial <array_type 7d76e1c0>
>    arg-type <array_type 7d76e1c0 type <integer_type 7d6d8150 char>
>        string-flag QI size <integer_cst 7d6c5208 8> unit size <integer_cst 7d6c5230 1>
>        align 8 symtab 0 alias set -1 canonical type 7d76e1c0
>        domain <integer_type 7d76e150 type <integer_type 7d6d8310 int4>
>            SI
>            size <integer_cst 7d6c5438 constant invariant 32>
>            unit size <integer_cst 7d6c5140 constant invariant 4>
>            align 32 symtab 0 alias set -1 canonical type 7d76e150 precision 32 min <integer_cst 7d6c58e8 1> max <integer_cst 7d6c58e8 1>>> chain <parm_decl 7d6cc208 _my_char>>
>
>
> I still see an array_type in there though I am not sure exactly what it
> is refering too.  I think it refers to the alignment of the parameter,
> the generated code is doing a 56 bit right shift (in a 64 bit register)
> of the parameter before using it and that is what causes the failure.
> It should not be doing any shifting.
>
> Steve Ellcey
> sje@cup.hp.com
>