On Wed, Oct 24, 2012 at 05:11:23PM +0200, Dodji Seketeli wrote:
> If I write exactly what you wrote here, I am getting an error for e.g:
>
> void
> bar ()
> {
> char bar[1] = {0};
> int n = 0;
>
> __builtin_memset (bar, 0, n);
> }
I see, the problem is that build_check_stmt is initially called on an
iterator in empty bb. Your solution is fine.
> > On the other side, you IMHO want to handle here also __atomic_* and
> > __sync_* builtins (not by using instrument_mem_region_access, but
> > just instrument_derefs
>
> Updated in the patch below.
case BUILT_IN_ATOMIC_ALWAYS_LOCK_FREE:
case BUILT_IN_ATOMIC_IS_LOCK_FREE:
I think don't touch the memory at all (or not necessarily),
and IMHO you don't want to handle the BUILT_IN_*_N variants either,
those are just FE builtins that are lowered to the corresponding
_{1,2,4,8,16} variants.
> @@ -661,13 +702,477 @@ instrument_derefs (gimple_stmt_iterator *iter, tree t,
> int volatilep = 0, unsignedp = 0;
> get_inner_reference (t, &bitsize, &bitpos, &offset,
> &mode, &unsignedp, &volatilep, false);
> - if (bitpos != 0 || bitsize != size_in_bytes * BITS_PER_UNIT)
> + if (bitpos % BITS_PER_UNIT || bitsize != size_in_bytes * BITS_PER_UNIT)
> return;
Shouldn't that be bitpos % (size_in_bytes * BITS_PER_UNIT) ?
1 byte or 2 byte access at bitpos 80 is fine, but 4 byte access is not.
Jakub
