Re: [PATCH] Allow DW_OP_GNU_uninit in dwarf_expr_require_composition

Tom Tromey
2016-10-10T22:41:14Z

>>>>> "Andreas" == Andreas Arnez <arnez@linux.vnet.ibm.com> writes:

Andreas> You mean to allow DW_OP_GNU_uninit to terminate any simple
Andreas> location description?

Yes.

>> That is, assuming DW_OP_GNU_uninit is useful at all.
>> Another option would be to deprecate it.

Andreas> Right, I wonder about its usefulness as well. For a variable
Andreas> with fixed location it may cover a small window where the
Andreas> compiler can be certain that the variable is uninitialized. I
Andreas> guess this *might* be useful sometimes?

Andreas> Is there even a DWARF issue for this? Or a formal
Andreas> specification?

I don't think so. Last time I looked into this all I was able to find
were the patch submissions to gcc and gdb. IIRC they weren't all that
informative though.

Tom