On Tue, 2009-07-21 at 16:56 -0700, Roland McGrath wrote: > > I must admit to not really see when you need the information "it got > > changed, but I put it back as is" versus "unchanged and in same place". > > Well, I think of "same_value" as meaning "that's not my register".
That is a nice way to think about it. That also makes more clear the idea of "changing it is for real". > > I admit to liking the return value 0 with *NOPS zero means CFI says the > > caller's REGNO is same_value" here of the original better than using > > DW_CFA_same_value as special marker. > > Do you like DW_CFA_nop any better? ;-) Bah, I meant DW_OP_same_value of course. And no, not really. Because like you said, that isn't a valid location expression. But it clearly depends on your preference. If you don't want to use "out of band signaling" then putting something, anything, in the returned Dwarf_Ops array is the way to go. But I actually prefer my Dwarf_Ops array to consist of only valid expressions. So I would use DW_OP_stack_value to indicate the "is a value" versus "is a location", but use length zero for undefined (since that is a valid expression with that meaning) and NULL for same_value (since it isn't expressible otherwise in a valid way). That said, if it would be a single DW_OP_nop or DW_OP_stack_value I would definitely cope. Cheers, Mark _______________________________________________ elfutils-devel mailing list [email protected] https://fedorahosted.org/mailman/listinfo/elfutils-devel
