Documentation has to change anyway, since the unw_init_local docs are
currently broken.
Decrementing the ip for my case (using unw_set_reg) gets me through a
few unw_step calls successfully, then crashes the program.
But I can't win this fight, so I'll quit.
Maybe I can get a new cursor init function added to the API. Would
the powers that be accept a change that added unw_init_local_signal,
which is just like unw_init_local except that it doesn't set
use_prev_instr? If not that name, the same thing by some other name?
I can post that change pretty quickly, if only someone will consider it.
Doug
Quoting Dave Watson <davejwat...@fb.com>:
On 03/29/17 04:51 PM, Doug Moore wrote:
Can’t we fix this whole problem by having getcontext subtract from
the pc to start with, so that nobody ever has to decrement the pc
on the first call to unw_step?
That would assume that the ucontext is usually from a signal frame
(third argument from a sigaction handler), which is probably pretty
common. It would break anyone that grabbed it outside a handler using
getcontext() instead of unw_getcontext() though.
The current documentation says:
```
On IA-64, unw_context_t has a layout that is compatible with that of
ucontext_t and such structures can be initialized with getcontext()
instead of unw_getcontext()
```
so it might be a somewhat interface breaking change.
Conversely, for your use case you might just be able to bump the ip by
one in the ucontext before the first unw_step()?
!DSPAM:10223,58dd225839344861828991!
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