Re: [Libunwind-devel] Exception handling routines on x86

[Arun Sharma]

On Sat, Feb 20, 2010 at 3:46 PM, address@hidden <address@hidden> wrote:

So, how should this problem be addressed cleanly? Should the registers be renumbered (via UNW_REG_* enums in libunwind-x86.h)? Or should _Unwind_SetGR and _Unwind_GetGR be patched to renumber the registers? Or do you have any other idea?

Renumbering doesn't work.

include/libunwind-x86.h:

       It would have been nice to use the same register numbering as

       DWARF, but that doesn't work because the libunwind requires

       that the exception argument registers be consecutive, which they

       wouldn't be with the DWARF numbering.  */

I think a patch along the lines of:

#ifdef __i386__

  unw_index = dwarf_to_unw_regnum_map[index];

#endif

// Use unw_index instead of index

might be better. Such a table exists in:

src/x86/Gglobal.c

 -Arun