On Thu, Jun 11, 2015 at 08:10:50AM +0200, Ingo Molnar wrote: > * Josh Poimboeuf <jpoim...@redhat.com> wrote: > > > I imagine that an automatic CFI annotation adder would walk through > > > functions > > > one instruction at a time and keep track of the frame state. If so, then > > > it > > > could verify that common jump targets had identical state and continue > > > walking > > > through them and annotating. I think this would get this case right, and > > > it > > > might be necessary anyway to handle jumps within functions. > > > > This would definitely add complexity to both asmvalidate and the CFI > > generator. > > In fact it sounds like it would push the CFI generator out of its current > > awk > > script territory and more into complex C code territory. > > I'd count that as a plus: awk isn't a common skillset while C is, and > properly > written it doesn't have to be _that_ complex.
The thing is, C is quite painful for text processing. And I think we'd have to do the analysis at the source text level in order to generate the .cfi_* instructions to pass to the gnu assembler. C would definitely make more sense when analyzing object code. In fact, asmvalidate is written in C. But then I guess we'd have to re-implement the .cfi stuff and populate the DWARF sections manually instead of letting the assembler do it. -- Josh -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
