[BUG/tracepoint/mips] MIPS tracepoint cannot collect stack info through collect *(unsigned char *)($sp)@512

[Hui Zhu]

Hi,

I try MIPS tracepoint but when I want to use collect *(unsigned char
*)($sp)@512 to collect the stack info, but I got:
(gdb) actions
Enter actions for tracepoint 1, one per line.
End with a line saying just "end".
>collect *(unsigned char *)($sp)@512
'sp' is a pseudo-register; GDB cannot yet trace pseudoregister contents.

That is because in ax-gdb.c:
reg = user_reg_map_name_to_regnum (exp->gdbarch, name, strlen (name));
if (reg == -1)
 internal_error (__FILE__, __LINE__,
 _("Register $%s not available"), name);
if (reg >= gdbarch_num_regs (exp->gdbarch))
 error (_("'%s' is a pseudo-register; "
  "GDB cannot yet trace pseudoregister contents."),
name);

In user_reg_map_name_to_regnum, it will call mips_register_name to get reg name:
But in function mips_register_name:
  /* Map [gdbarch_num_regs .. 2*gdbarch_num_regs) onto the raw registers,
     but then don't make the raw register names visible.  */
  int rawnum = regno % gdbarch_num_regs (gdbarch);
  if (regno < gdbarch_num_regs (gdbarch))
    return "";

So it make user_reg_map_name_to_regnum just can return the "reg"
bigger than gdbarch_num_regs.


Then it will get this error message.  Do you have some way to handle this issue?

Thanks,
Hui