rx: Treat scalars larger than 8 bytes as aggregates in rx_push_dummy_call

  This patch fixes the following failures (which are also GDB internal errors)
for the -m64bit-doubles multilib:

FAIL: gdb.base/callfuncs.exp: p t_double_complex_values(dc1, dc2) (GDB internal error)
FAIL: gdb.base/callfuncs.exp: p t_double_complex_values(dc3, dc4) (GDB internal error)
FAIL: gdb.base/callfuncs.exp: p t_double_complex_many_args(dc1, dc2, dc3, dc4, dc1, dc2, dc3, dc4, dc1, dc2, dc3, dc4, dc1, dc2, dc3, dc4) (GDB internal error)
FAIL: gdb.base/callfuncs.exp: p t_double_complex_many_args(dc1, dc1, dc1, dc1, dc1, dc1, dc1, dc1, dc1, dc1, dc1, dc1, dc1, dc1, dc1, dc1) (GDB internal error)
FAIL: gdb.base/callfuncs.exp: p t_long_double_complex_values(ldc1, ldc2) (GDB internal error)
FAIL: gdb.base/callfuncs.exp: p t_long_double_complex_values(ldc3, ldc4) (GDB internal error)
FAIL: gdb.base/callfuncs.exp: p t_long_double_complex_many_args(ldc1, ldc2, ldc3, ldc4, ldc1, ldc2, ldc3, ldc4, ldc1, ldc2, ldc3, ldc4, ldc1, ldc2, ldc3, ldc4) (GDB internal error)
FAIL: gdb.base/callfuncs.exp: p t_long_double_complex_many_args(ldc1, ldc1, ldc1, ldc1, ldc1, ldc1, ldc1,ldc1, ldc1, ldc1, ldc1, ldc1, ldc1, ldc1, ldc1, ldc1) (GDB internal error)
FAIL: gdb.base/callfuncs.exp: noproto: p t_double_complex_values(dc1, dc2) (GDB internal error)
FAIL: gdb.base/callfuncs.exp: noproto: p t_double_complex_values(dc3, dc4) (GDB internal error)
FAIL: gdb.base/callfuncs.exp: noproto: p t_double_complex_many_args(dc1, dc2, dc3, dc4, dc1, dc2, dc3, dc4, dc1, dc2, dc3, dc4, dc1, dc2, dc3, dc4) (GDB internal error)
FAIL: gdb.base/callfuncs.exp: noproto: p t_double_complex_many_args(dc1, dc1, dc1, dc1, dc1, dc1, dc1, dc1, dc1, dc1, dc1, dc1, dc1, dc1, dc1, dc1) (GDB internal error)
FAIL: gdb.base/callfuncs.exp: noproto: p t_long_double_complex_values(ldc1, ldc2) (GDB internal error)
FAIL: gdb.base/callfuncs.exp: noproto: p t_long_double_complex_values(ldc3, ldc4) (GDB internal error)
FAIL: gdb.base/callfuncs.exp: noproto: p t_long_double_complex_many_args(ldc1, ldc2, ldc3, ldc4, ldc1, ldc2, ldc3, ldc4, ldc1, ldc2, ldc3, ldc4, ldc1, ldc2, ldc3, ldc4) (GDB internal error)
FAIL: gdb.base/callfuncs.exp: noproto: p t_long_double_complex_many_args(ldc1, ldc1, ldc1, ldc1, ldc1, ldc1, ldc1,ldc1, ldc1, ldc1, ldc1, ldc1, ldc1, ldc1, ldc1, ldc1) (GDB internal error)
FAIL: gdb.base/varargs.exp: print find_max_double_real(4, dc1, dc2, dc3, dc4) (GDB internal error)
FAIL: gdb.base/varargs.exp: print find_max_long_double_real(4, ldc1, ldc2, ldc3, ldc4) (GDB internal error)

The assertion failure which is tripped is:

	      gdb_assert (arg_size <= 4);

While it may seem that the patch ought to disallow scalars larger than
4, scalars of size 8 are explicitly handled by the code elsewhere.

This came up because gcc has a complex type that is 16 bytes in length
when 64-bit doubles are used.

gdb/ChangeLog:
    
    	* rx-tdep.c (rx_push_dummy_call): Treat scalars larger than 8
    	bytes as aggregates.
---
 gdb/rx-tdep.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
  

Hi Kevin,

> gdb/ChangeLog:
>     
>     	* rx-tdep.c (rx_push_dummy_call): Treat scalars larger than 8
>     	bytes as aggregates.

I'll trust you on RX matters, and the contents of the message
seems to indicate that you would have tested the change using
our testsuite, so...

OK with me! :-)

> ---
>  gdb/rx-tdep.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/gdb/rx-tdep.c b/gdb/rx-tdep.c
> index 2732608..904aebd 100644
> --- a/gdb/rx-tdep.c
> +++ b/gdb/rx-tdep.c
> @@ -813,7 +813,8 @@ rx_push_dummy_call (struct gdbarch *gdbarch, struct value *function,
>  						struct_addr);
>  	    }
>  	  else if (TYPE_CODE (arg_type) != TYPE_CODE_STRUCT
> -		   && TYPE_CODE (arg_type) != TYPE_CODE_UNION)
> +		   && TYPE_CODE (arg_type) != TYPE_CODE_UNION
> +		   && arg_size <= 8)
>  	    {
>  	      /* Argument is a scalar.  */
>  	      if (arg_size == 8)
  

On Tue, 26 Jan 2016 16:39:38 +0400
Joel Brobecker <brobecker@adacore.com> wrote:

> Hi Kevin,
> 
> > gdb/ChangeLog:
> >     
> >     	* rx-tdep.c (rx_push_dummy_call): Treat scalars larger than 8
> >     	bytes as aggregates.
> 
> I'll trust you on RX matters, and the contents of the message
> seems to indicate that you would have tested the change using
> our testsuite, so...
> 
> OK with me! :-)

Hi Joel,

Thanks for looking it over.

It's pushed now.

Kevin