Re: [PATCH] Add support for Tilera TILE-Gx processor (part 1/3: gdb)

[Pedro Alves <palves@redhat.com>]

On 05/24/2012 08:26 PM, Jeff Kenton wrote:

> On 05/23/2012 01:33 PM, Pedro Alves wrote:
>> Hi Jeff,
>>
>> On 05/21/2012 03:23 PM, Jeff Kenton wrote:
>>
>>
> 
> -  Comments applied.
> -  SIGTRAMP frame handling improved.
> -  Patch attached.


For the future, it's easier for the reviewer if you reply to the issues
and questions raised.  For example, in patch 2, I'm left wondering if the
ps_get_thread_area addition fixed any testsuite failures, indicating it is
correct.  I'm also left wondering what does "improved" mean
(probably fixed something in the testsuite?).

> diff -r -u -N /home/packages/gdb-7.4x/gdb/tilegx-linux-tdep.c ./gdb/tilegx-linux-tdep.c
> --- /home/packages/gdb-7.4x/gdb/tilegx-linux-tdep.c	1969-12-31 19:00:00.000000000 -0500
> +++ ./gdb/tilegx-linux-tdep.c	2012-05-24 13:43:30.089276000 -0400

> +/* Supply raw registers from REGCACHE to REGS.  */
> +
> +/* TILE-Gx has 56 general purpose registers,
> +   plus 8 special general purpose registers (network and ZERO),
> +   plus 1 magic register (PC == 64).
> +   We only need the following 2 enums here.  */
> +
> +enum {
> +       E_NUM_EASY_REGS = 56,
> +       E_PC_REGNUM = 64
> +};

> +

> +enum { tilegx_reg_size = 8 };



I didn't pay close attention to what these two enums were before.  The standard thing
to do instead of defining tilegx_reg_size twice, and hacking up that short
enum for the register numbers, is to move the register numbers enum from
tilegx-tdep.c to and tilegx-tdep.h file, and include that where necessary,
so we only have one place with the register numbers.
'E_' isn't a great prefix (does it mean 'enum'?), so please replace it with
something like TILEGX_PC_REGNUM, etc. along with the move.

> +/* OS specific initialization of gdbarch.  */
> +
> +static void
> +tilegx_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
> +{
> +  int arch_size = 64;
> +
> +  /* Handle arch_size == 32 or 64.  Default to 64.  */
> +  if (info.abfd)
> +    arch_size = bfd_get_arch_size (info.abfd);
> +
> +  if (arch_size != 32)
> +    arch_size = 64;


Why is this 'if' necessary?  Does bfd_get_arch_size ever return anything
not 32 or 64?  In any case, you can just use gdbarch_addr_bit here,
as tilegx_gdbarch_init has already done the similar bfd_get_arch_size bit.



> +/* This is the implementation of gdbarch method breakpoint_from_pc.  */
> +
> +static const unsigned char *
> +tilegx_breakpoint_from_pc (struct gdbarch *gdbarch,
> +                           CORE_ADDR *pcptr, int *lenptr)
> +{
> +  /* 64-bit pattern for a { bpt ; nop } bundle.  */
> +  static unsigned char breakpoint[] =


static const.

> +    { 0x00, 0x50, 0x48, 0x51, 0xae, 0x44, 0x6a, 0x28 };
> +
> +  *lenptr = sizeof (breakpoint);
> +  return breakpoint;
> +}
> +

I think we're getting close.  If Joel or anyone else has further comments,
the next iteration should be about ready to go in.

-- 
Pedro Alves