Re: /gdb/regcache.c question

[Mark Kettenis <mark.kettenis@xs4all.nl>]

> From: Der Herr Hofrat <der.herr@hofr.at>
> Date: Mon, 3 Apr 2006 09:57:43 +0200 (CEST)
> 
> Hi !
> 
>  while implementing tracepoints I ran acros a little problem with 
>  gdb/regcache.c - the behavior is not really an error its just overly 
>  strict for interactive input, obviously regache.c is assuming 
>  automatic generation of registers lists only.
> 
> (gdb) actions
> Enter actions for tracepoint 1, one per line.
> End with a line saying just "end".
> > collect $regs
> > end
> (gdb) trace junk2
> Tracepoint 2 at 0x80483eb: file hello.c, line 27.
> (gdb) actions
> Enter actions for tracepoint 2, one per line.
> End with a line saying just "end".
> > collect $sp
> regcache.c:163: internal-error: register_type: Assertion `regnum >= 0 && regnum
> < descr->nr_cooked_registers' failed.
> A problem internal to GDB has been detected,
> further debugging may prove unreliable.
> Quit this debugging session? (y or n) n
> 
> regcache.c:163: internal-error: register_type: Assertion `regnum >= 0 && regnum
> < descr->nr_cooked_registers' failed.
> A problem internal to GDB has been detected,
> further debugging may prove unreliable.
> Create a core file of GDB? (y or n) y
> 
>  
>  The trigger is gdb_assert in line 163:
> 
> gdb/regcache.c:159-165
> struct type *
> register_type (struct gdbarch *gdbarch, int regnum)
> {
>   struct regcache_descr *descr = regcache_descr (gdbarch);
>   gdb_assert (regnum >= 0 && regnum < descr->nr_cooked_registers);
>   return descr->register_type[regnum];
> }
> 
> 
>  So a simple misstyp of the register name runs into an assertion
>  with a core file dumped - this makes sense for automatic generation
>  - but for tracepoints you need to manually be able to pass
>  registers with collect $REGNAME , and for that case gdb_assert ->
>  corfile is a little harsh on the user.

I don't understand what you're doing here, but that gdb_assert (and
all gdb_asserts in the code) is checking for a "should not happen"
condition.  If you hit one, it means there's a bug in some other piece
of gdb code.  You should find and fix that bug.

Mark