On 2020-02-28 22:32, Florian Weimer wrote: > * J. W. Jagersma: > >> The call instruction is just a practical example. The problem I want to >> address is that no exception handling information is generated at all >> for asm statements. Other operations, eg. memory access, division, etc >> could trap and throw an exception. The unwind tables should cover this. > > I think permitted uses of asm cannot do anything that would make the > tables invalid, at least for DWARF unwinding information. I don't see how a trapping instruction in asm would invalidate the unwind table. An explicit call, maybe, but as I said that was only an example. The problem is that there is no unwind table at all. > DWARF does not need to annotate any instruction that might throw (which > would be every instruction in case of asynchronous unwind tables). But it should, if the instruction appears in a try block. Without that it is impossible to catch the exception.
