H8300 Patch - Fix GDB crash problem when object file of different H8 cpu is loaded

[Michael Snyder]

Andrew Cagney wrote:
>> Hi,
>>
>> Currently if you are debugging one object and load another object of 
>> different H8 CPU then the GDB crashes in h8300_register_name() saying 
>> "invalid register number". This is because in gdbarch_init we are 
>> returning existing gdbarch but the globals h8300hmode, h8300smode, 
>> etc. are not set again corresponding to newly loaded object.
>>
>> The patch below initializes these globals before returning existing 
>> gdbarch.
> 
> 
> Unfortunatly this isn't the right way to go.  Because it is now possible 
> for GDB can have more than one active architecture, code that rely on 
> global state can no longer work.  The globals:
> 
>  > +      h8300_normal_mode = 0;
>  > +      h8300sxmode = 0;
>  > +      h8300smode = 0;
>  > +      h8300hmode = 0;
> 
> will need to be eliminated. 

Would it be appropriate to move them into the gdbarch_tdep struct?

 > Looking at your patch it doesn't look too
> bad.  Given h8300smode, I'd replace it with a function vis:
> 
> int
> h8300smode (struct gdbarch *gdbarch)
> {
>   return gdbarch_bfd_arch_info (current_gdbarch)->mach == bfd_mach_h8300s
> }
> 
> and called:
>     
>     if (h8300smode (current_gdbarch))
> 
> Andrew

The only problem is, these functions would be called from the sim.
Since the sim doesn't know about struct gdbarch, and since you've
written them as using the global current_gdbarch anyway, they
probably should have no argument.

Michael

> 
>> Changelog -
>> 2003-11-14  Dhananjay Deshpande <dhananjayd@kpitcummins.com>
>>         * gdb/h8300-tdep.c (h8300_gdbarch_init): Set globals before 
>> returning existing gdbarch
>>
>> ================================================================================= 
>>
>> --- gdb/h8300-tdep.c.old    2003-11-12 13:51:36.000000000 +0530
>> +++ gdb/h8300-tdep.c    2003-11-14 11:08:29.000000000 +0530
>> @@ -1176,6 +1176,53 @@ h8300_gdbarch_init (struct gdbarch_info    
>> struct gdbarch_tdep *tdep = NULL;
>>    struct gdbarch *gdbarch;
>>  
>> +  /* Set globals */
>> +  switch (info.bfd_arch_info->mach)
>> +    {
>> +    case bfd_mach_h8300:
>> +      h8300_normal_mode = 0;
>> +      h8300sxmode = 0;
>> +      h8300smode = 0;
>> +      h8300hmode = 0;
>> +      break;
>> +    case bfd_mach_h8300h:
>> +      h8300_normal_mode = 0;
>> +      h8300sxmode = 0;
>> +      h8300smode = 0;
>> +      h8300hmode = 1;
>> +      break;
>> +    case bfd_mach_h8300hn:
>> +      h8300_normal_mode = 1;
>> +      h8300sxmode = 0;
>> +      h8300smode = 0;
>> +      h8300hmode = 1;
>> +      break;
>> +    case bfd_mach_h8300s:
>> +      h8300_normal_mode = 0;
>> +      h8300sxmode = 0;
>> +      h8300smode = 1;
>> +      h8300hmode = 1;
>> +      break;
>> +    case bfd_mach_h8300sn:
>> +      h8300_normal_mode = 1;
>> +      h8300sxmode = 0;
>> +      h8300smode = 1;
>> +      h8300hmode = 1;
>> +      break;
>> +    case bfd_mach_h8300sx:
>> +      h8300_normal_mode = 0;
>> +      h8300sxmode = 1;
>> +      h8300smode = 1;
>> +      h8300hmode = 1;
>> +      break;
>> +    case bfd_mach_h8300sxn:
>> +      h8300_normal_mode = 1;
>> +      h8300sxmode = 1;
>> +      h8300smode = 1;
>> +      h8300hmode = 1;
>> +      break;
>> +    }
>> +
>>    arches = gdbarch_list_lookup_by_info (arches, &info);
>>    if (arches != NULL)
>>      return arches->gdbarch;
>> @@ -1192,9 +1239,6 @@ h8300_gdbarch_init (struct gdbarch_info    
>> switch (info.bfd_arch_info->mach)
>>      {
>>      case bfd_mach_h8300:
>> -      h8300sxmode = 0;
>> -      h8300smode = 0;
>> -      h8300hmode = 0;
>>        set_gdbarch_num_regs (gdbarch, 13);
>>        set_gdbarch_num_pseudo_regs (gdbarch, 1);
>>        set_gdbarch_ecoff_reg_to_regnum (gdbarch, 
>> h8300_dbg_reg_to_regnum);
>> @@ -1210,9 +1254,6 @@ h8300_gdbarch_init (struct gdbarch_info        
>> break;
>>      case bfd_mach_h8300h:
>>      case bfd_mach_h8300hn:
>> -      h8300sxmode = 0;
>> -      h8300smode = 0;
>> -      h8300hmode = 1;
>>        set_gdbarch_num_regs (gdbarch, 13);
>>        set_gdbarch_num_pseudo_regs (gdbarch, 1);
>>        set_gdbarch_ecoff_reg_to_regnum (gdbarch, 
>> h8300_dbg_reg_to_regnum);
>> @@ -1222,13 +1263,11 @@ h8300_gdbarch_init (struct gdbarch_info        
>> set_gdbarch_register_name (gdbarch, h8300_register_name);
>>        if(info.bfd_arch_info->mach != bfd_mach_h8300hn)
>>          {
>> -          h8300_normal_mode = 0;
>>            set_gdbarch_ptr_bit (gdbarch, 4 * TARGET_CHAR_BIT);
>>            set_gdbarch_addr_bit (gdbarch, 4 * TARGET_CHAR_BIT);
>>          }
>>        else
>>          {
>> -          h8300_normal_mode = 1;
>>            set_gdbarch_ptr_bit (gdbarch, 2 * TARGET_CHAR_BIT);
>>            set_gdbarch_addr_bit (gdbarch, 2 * TARGET_CHAR_BIT);
>>          }
>> @@ -1238,9 +1277,6 @@ h8300_gdbarch_init (struct gdbarch_info        
>> break;
>>      case bfd_mach_h8300s:
>>      case bfd_mach_h8300sn:
>> -      h8300sxmode = 0;
>> -      h8300smode = 1;
>> -      h8300hmode = 1;
>>        set_gdbarch_num_regs (gdbarch, 16);
>>        set_gdbarch_num_pseudo_regs (gdbarch, 2);
>>        set_gdbarch_ecoff_reg_to_regnum (gdbarch, 
>> h8300s_dbg_reg_to_regnum);
>> @@ -1250,13 +1286,11 @@ h8300_gdbarch_init (struct gdbarch_info        
>> set_gdbarch_register_name (gdbarch, h8300s_register_name);
>>        if(info.bfd_arch_info->mach != bfd_mach_h8300sn)
>>          {
>> -          h8300_normal_mode = 0;
>>            set_gdbarch_ptr_bit (gdbarch, 4 * TARGET_CHAR_BIT);
>>            set_gdbarch_addr_bit (gdbarch, 4 * TARGET_CHAR_BIT);
>>          }
>>        else
>>          {
>> -          h8300_normal_mode = 1;
>>            set_gdbarch_ptr_bit (gdbarch, 2 * TARGET_CHAR_BIT);
>>            set_gdbarch_addr_bit (gdbarch, 2 * TARGET_CHAR_BIT);
>>          }
>> @@ -1266,9 +1300,6 @@ h8300_gdbarch_init (struct gdbarch_info        
>> break;
>>      case bfd_mach_h8300sx:
>>      case bfd_mach_h8300sxn:
>> -      h8300sxmode = 1;
>> -      h8300smode = 1;
>> -      h8300hmode = 1;
>>        set_gdbarch_num_regs (gdbarch, 18);
>>        set_gdbarch_num_pseudo_regs (gdbarch, 2);
>>        set_gdbarch_ecoff_reg_to_regnum (gdbarch, 
>> h8300s_dbg_reg_to_regnum);
>> @@ -1278,13 +1309,11 @@ h8300_gdbarch_init (struct gdbarch_info        
>> set_gdbarch_register_name (gdbarch, h8300sx_register_name);
>>        if(info.bfd_arch_info->mach != bfd_mach_h8300sxn)
>>          {
>> -          h8300_normal_mode = 0;
>>            set_gdbarch_ptr_bit (gdbarch, 4 * TARGET_CHAR_BIT);
>>            set_gdbarch_addr_bit (gdbarch, 4 * TARGET_CHAR_BIT);
>>          }
>>        else
>>          {
>> -          h8300_normal_mode = 1;
>>            set_gdbarch_ptr_bit (gdbarch, 2 * TARGET_CHAR_BIT);
>>            set_gdbarch_addr_bit (gdbarch, 2 * TARGET_CHAR_BIT);
>>          }
>> ================================================================================= 
>>
>>
> 
> 
>