Hi,
The patch below addresses PR68270. could you please take a look?
2016-11-25 Alexander Ivchenko <aivch...@gmail.com>
* c-family/c.opt (flag_chkp_flexible_struct_trailing_arrays):
Add new option.
* tree-chkp.c (chkp_parse_array_and_component_ref): Forbid
narrowing when chkp_parse_array_and_component_ref is used and
the ARRAY_REF points to an array in the end of the struct.
diff --git a/gcc/c-family/c.opt b/gcc/c-family/c.opt
index 7d8a726..e45d6a2 100644
--- a/gcc/c-family/c.opt
+++ b/gcc/c-family/c.opt
@@ -1166,6 +1166,11 @@ C ObjC C++ ObjC++ LTO RejectNegative Report
Var(flag_chkp_narrow_to_innermost_ar
Forces Pointer Bounds Checker to use bounds of the innermost arrays in case of
nested static arryas access. By default outermost array is used.
+fchkp-flexible-struct-trailing-arrays
+C ObjC C++ ObjC++ LTO RejectNegative Report
Var(flag_chkp_flexible_struct_trailing_arrays)
+Allow Pointer Bounds Checker to treat all trailing arrays in structures as
+possibly flexible.
+
fchkp-optimize
C ObjC C++ ObjC++ LTO Report Var(flag_chkp_optimize) Init(-1)
Allow Pointer Bounds Checker optimizations. By default allowed
diff --git a/gcc/tree-chkp.c b/gcc/tree-chkp.c
index 2769682..40f99c3 100644
--- a/gcc/tree-chkp.c
+++ b/gcc/tree-chkp.c
@@ -3425,7 +3425,9 @@ chkp_parse_array_and_component_ref (tree node, tree *ptr,
if (flag_chkp_narrow_bounds
&& !flag_chkp_narrow_to_innermost_arrray
&& (!last_comp
- || chkp_may_narrow_to_field (TREE_OPERAND (last_comp, 1))))
+ || (chkp_may_narrow_to_field (TREE_OPERAND (last_comp, 1))
+ && !(flag_chkp_flexible_struct_trailing_arrays
+ && array_at_struct_end_p (var)))))
{
comp_to_narrow = last_comp;
break;
