* Josh Poimboeuf <jpoim...@redhat.com> wrote:
> > How are you handling control flow?
>
> Control flow of what?
>
> > > Here's the struct in its current state:
> > >
> > > #define UNDWARF_REG_UNDEFINED 0
> > > #define UNDWARF_REG_CFA 1
> > > #define UNDWARF_REG_SP 2
> > > #define UNDWARF_REG_FP 3
> > > #define UNDWARF_REG_SP_INDIRECT 4
> > > #define UNDWARF_REG_FP_INDIRECT 5
> > > #define UNDWARF_REG_R10 6
> > > #define UNDWARF_REG_DI 7
> > > #define UNDWARF_REG_DX 8
> > >
> >
> > Why only those registers? Also, if you have the option I would really
> > suggest using the actual x86 register numbers (ax, ex, dx, bx, sp, bp,
> > si, di, r8-r15 in that order.)
>
> Those are the only registers which are ever needed as the base for
> finding the previous stack frame. 99% of the time it's sp or bp, the
> other registers are needed for aligned stacks and entry code.
>
> Using the actual register numbers isn't an option because I don't need
> them all and they need to fit in a small number of bits.
>
> This construct might be useful for other arches, which is why I called
> it "FP" instead of "BP". But then I ruined that with the last 3 :-)
Please call it BP - 'FP' can easily be read as floating-point, making it all
super-confusing. We should use canonical x86 register names and ordering - even
if not all registers are used straight away.
Thanks,
Ingo
