Re: [PATCH][SH] invalid registers

[Andrew STUBBS <andrew.stubbs@st.com>]

Daniel Jacobowitz wrote:
> This is OK.  Only S/390 uses the frame_init_reg hook this way today,
> but it seems sensible.  But please wait a day or two in case anyone has
> comments on the downside.

Hmmm, perhaps that ought to be fixed. I don't believe all those target 
really *know* what the value of all registers is in every frame.

> The downside is that you can't do this:
> 
> (gdb) break *abort
> (gdb) continue
> ...
> (gdb) up
> (gdb) info registers
> 
> Instead, you have to look at the registers while you're in the bottom
> frame (i.e. abort) instead of the aborting function.

In your example _we_ know that the values are real, but the debugger
does not, and, in my opinion, should not present them as if it does.

> Would it be more useful if GDB could output "0x40000000 (may be
> clobbered)" somehow in info regs for DWARF2_FRAME_REG_UNDEFINED?
> But, not a big deal either way.

Yes, that might be a suitable compromise, but not for
DWARF2_FRAME_REG_UNDEFINED - that value really means it when it comes
from dwarf. Perhaps another value.

In any case, a 'day or two' has passed and nobody has said anything. Am
I OK to commit this?

Andrew