Re: [PATCH][ubsan] Add VLA bound instrumentation

[Marek Polacek <polacek@redhat.com>]

On Wed, Oct 30, 2013 at 03:41:53PM -0700, Mike Stump wrote:
> The dtors only run, after the ctors run.  We mark where the ctors finish spot, as the _start_ of the region for which we have to clean up.  Really, the cleanup has nothing to do with ctors.  You can have dtors, without any ctors, or ctors, without any dtors.
> 
> {
>   decl d;
>   s;
> }
> 
> transforms into:
> 
> <-----  start of lifetime of the storage for d
> ctor(d)
> <-----  start of lifetime of the fully constructed object d
> s;
> <-----  end of lifetime of fully constructed object d
> dtor(d)
> <-----  end of the storage of d
> 
> CLEANUP_STMT documents when the region protected by the cleanup starts.  One want to describe that region is, the end of the ctors, if any, else after the storage is allocated.  In the above, that is the second <---- spot.
> 
> Now, in the trees, the above is decl d; ctors; CLEANUP_STMT (s, dtors, d).
> 
> s is the region for which the cleanups are active for.  dtors is the cleanup to perform on transfer out of that region, and d is the decl related to the actions in dtors.

I see now.  Thanks very much, Mike.

	Marek