Re: Add DW_OP_GNU_encoded_addr

[Richard Henderson <rth at redhat dot com>]

Chris Lattner wrote:
> >  asm(    "test something
> >     jnz 1f
> >     .section text2,\"ax\"
> > 1:    .cfi_startproc simple
> >     .cfi_def_cfa %%esp, 0
> >     .cfi_val_encoded_addr %%eip, 0x1b, 11f
> >     <do-some-stuff>
> >     jmp 11f
> >     .cfi_endproc
> >     .previous
> > 11:");
> >
> > This is an idiom that shows up several places in glibc and in the
> > kernel.  In glibc, Jakub currently goes to heroic efforts to
> > generate the unwind information by hand, but this code is what you
> > might call write-only i.e. intensely difficult to modify.
>
> Does this idiom work if the inline asm block is duplicated by the 
> compiler (e.g. due to inlining, loop unrolling, etc)?

Yes.


r~