Re: [PATCH 1/4] 'catch syscall' feature -- Architecture-independent part

[Pedro Alves <pedro at codesourcery dot com>]

On Friday 07 November 2008 03:29:25, Sérgio Durigan Júnior wrote:

> Ok, I'll try to put the syscall_state in 'struct lwp_info'. Honestly, I
> don't remember now why I've chosen to put this variable inside
> thread_info, but of course you're way more capable of telling me how to
> make my design be more clever (and look more like GDB) :-).

Nah, you're doing yourself just fine.  :-)

An alternative would be to add a new TARGET_WAITKIND_SYSCALL, for
targets that don't distinguish entry/exit, but this leaves me yet
to wonder:

If there any other way to distinguish entry/exit other than a toggle?
Toggles are prone to be fallible.  E.g., if you *attach* to a program that
is doing a long syscall, and then start tracing that syscall,
is it possible that you hit the syscall exit first, so your toggle will
be inverted?  That is, you'll report a syscall entry, when in fact, it
was a syscall exit, and so on for the following syscalls of the same lwp.

-- 
Pedro Alves