Re: [patch/rfc] Add a sentinel frame

Michal Ludvig
2003-02-28T13:02:42Z

Andrew Cagney wrote:
> To give this x86-64 thread clear closure. The internal-error you are
> seeing from the new frame code is now, officially, "not-a-frame-bug".

Yes, I've already realised so. Thank you for confirmation.

> The underlying problem is caused by a design flaw (one of many) in the
> original CFI code (on which the x86-64 depends). It's trying to use the
> CFI unwinder on a block of code that either: has no CFI information; or
> has CFI information that isn't relevant to the stack frame being
> unwound. Using CFI to unwind such a frame is meaningless.
[...]
> To fix this problem, the x86-64 will need to implement both that and the
> save_dummy_frame_tos() method.

OK. So, first I need to convert x86-64 target to use all the new
frame-id stuff I think. And then implement handling of different frame
types (normal (CFI), dummy, sigtramp, and specifically for x86-64 also
normal frames without CFI debug info).
Basically all calls to cfi_*() functions from x86-64-*.c files should
become x86_64_*() functions that call the appropriate cfi_*() functions
if needed, or a frame-type specific thing otherwise.
Correct?

Michal Ludvig
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