Re: [RFA] mips 32/64 register/stack fix

[Andrew Cagney <cagney@gnu.org>]

> Andrew Cagney wrote:
> 
>>> #0  register_size (gdbarch=0x84093e8, regnum=120)
>>
>>
>>
>> 120 looks large enough to be cooked (but to confirm this can you look at "maint print raw-registers".  This will also tell us the register's type, and hence confirm the size.
> 
> 
> Yes, raw is from 0 to 89, and cooked is from 90 to 179.
> regcache->descr->sizeof_register is as follows:
> 8 for all raw
> 8 for the first 70 cooked
> 4 for the last 20 cooked
> 
> register_type looks like:
> raw:
> 38 @ int64
> 32 @ double64
> 20 @ int64
> cooked:
> 38 @ int64
> 32 @ double64
> 20 @ int32

good.

>> Given that you see 8, this suggests that the register's type is wrong (see mips_register_type).
> 
> 
> It looks to me as if mips_register_type relies on mips_regsize.
> Which returns 8.  Yep, and mips_register_type (120) returns int64_t.
> 
> But mips_saved_regsize (tdep) returns 4 (as it should, I guess).
> 
>> Also, what information is available in the object file header?
> 
> 
> Can you be more specific?
[...]
> Here's your tdep info:
> {elf_flags = 1610625025, mips_abi = MIPS_ABI_EABI32,

I was looking to see if anything like that was present -> it is clearly 
identified as a 32-bit ABI binary.

I think the bug is in mips_register_type, the tail end should probably 
be changed to read something like:

   else if (regnum >= NUM_REGS
	   && gdbarch_tdep (gdbarch)->mips64_transfers_32bit_regs_p)
     /* The target, while using a 64-bit raw register buffer, is only
        transfering 32-bits of each integer register.  Reflect this in
        the cooked/pseudo register value.  */
     return builtin_type_int32;
   else if (regnum > NUM_REGS
	   && mips_saved_regsize (gdbarch) == 4)
     /* A 32-bit ABI such as o32 possibly running on a 64-bit ISA.  */
     return builtin_type_int32;
   else if (mips_regsize (gdbarch) == 8)
     /* 64-bit ISA.  */
     return builtin_type_int64;
   else
     /* 32-bit ISA.  */
     return builtin_type_int32;

Andrew