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Re: Checking if addess is on stack?
> From: Vladimir Prus <ghost@cs.msu.su>
> Date: Thu, 20 Apr 2006 14:26:58 +0400
> Cc: gdb@sources.redhat.com
>
> I'm not sure that's exactly what I need. This way, watchpoint will be
> automatically inserted when I enter 'do_that', but as soon as I leave
> 'do_that', gdb will remove wathchpoint because 'ptr' has gone out of scope.
> This will prevent me from catching accesses to ptr->i made outside of the
> function where 'ptr' is valid. Am I missing something?
Perhaps _I_ am missing something. Isn't `ptr' a variable that is
local to the function `do_that'? I thought it was; if so, then it
couldn't possibly be accessed after `do_that' returns, because all
locals are popped off the stack when `do_that' returns. These locals
will get entirely new values when `do_that' is entered the next time.
(If you want to catch accesses to the address where `ptr' _was_ on the
stack, then you really need to set the wathchpoint on an absolute
address. But watching addresses on the stack beyond the stack top is
a very unusual thing to do, so I don't think this is what your users
would need.)
OTOH, if by ``leave `do_that''' you mean that `do_that' calls some
other function, then `ptr' does not go off the scope, and GDB should
not delete the watchpoint.
Does this make sense?