Re: [PATCH] Map registers to remote numbers when encoding an ax_reg or ax_reg_mask operation

[Antoine Tremblay <antoine dot tremblay at ericsson dot com>]

Pedro Alves writes:

> On 02/25/2016 01:25 PM, Antoine Tremblay wrote:
>> When encoding the agent expression operation ax_reg or ax_reg_mask, the
>> register number used is internal to GDB. However GDBServer expects a tdesc
>> based number.
>> 
>> This usually does not cause a problem since at the moment, for raw
>> registers GDBServer R trace action ignores the register mask and just
>> collects all registers.
>> 
>> It can be a problem, however with pseudo registers on some platforms if the
>> tdesc number doesn't match the GDB internal register number.
>> 
>> This is the case with ARM, the upcoming ARM tracepoint support, fails
>> these test cases without this patch:
>> 
>> gdb.trace/collection.exp: collect register locals collectively:*
>> 
>> GDBSever would exit with: unhandled register size
>> Since the register number is not mapped.
>> 
>> This patch fixes these issues by calling gdbarch_remote_register_number
>> before encoding the register number in the ax_reg or ax_reg_mask operation.
>> 
>> Tested on x86 native-gdbserver no regressions observed.
>
>>    else
>>      {
>> -      int byte = reg / 8;
>> +      int byte = 0;
>
> No need to zero initialize.

OK.

>
>> +
>> +      /* Get the remote register number.  */
>> +      reg = gdbarch_remote_register_number (ax->gdbarch, reg);
>> +      byte = reg / 8;
>>  
>>        /* Grow the bit mask if necessary.  */
>>        if (byte >= ax->reg_mask_len)
>> 
>
> OK with ChangeLog entry.

Oops, yes I'll add a ChangeLog sorry about that.

Thanks,
Antoine