https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101836
--- Comment #15 from qinzhao at gcc dot gnu.org ---
the following patch will fix the issue with this testing case:
[opc@qinzhao-ol8u3-x86 gcc]$ git diff
diff --git a/gcc/tree-object-size.cc b/gcc/tree-object-size.cc
index 5ca87ae3504..7df092346b9 100644
--- a/gcc/tree-object-size.cc
+++ b/gcc/tree-object-size.cc
@@ -604,9 +604,8 @@ addr_object_size (struct object_size_info *osi, const_tree
ptr,
else if (var != pt_var && TREE_CODE (pt_var) == MEM_REF)
{
tree v = var;
- /* For &X->fld, compute object size only if fld isn't the last
- field, as struct { int i; char c[1]; } is often used instead
- of flexible array member. */
+ /* For &X->fld, compute object size if fld isn't a flexible array
+ member. */
while (v && v != pt_var)
switch (TREE_CODE (v))
{
@@ -645,12 +644,19 @@ addr_object_size (struct object_size_info *osi,
const_tree ptr,
&& TREE_CODE (TREE_TYPE (TREE_OPERAND (v, 0)))
== RECORD_TYPE)
{
- tree fld_chain = DECL_CHAIN (TREE_OPERAND (v, 1));
- for (; fld_chain; fld_chain = DECL_CHAIN (fld_chain))
- if (TREE_CODE (fld_chain) == FIELD_DECL)
- break;
-
- if (fld_chain)
+ bool is_flexible_array = false;
+ /* Set for accesses to special trailing arrays. */
+ special_array_member sam{ };
+
+ tree refsize = component_ref_size (v, &sam);
+ /* if the array is a special trailing array, don't
compute
+ * its size, otherwise, treat it as a normal array. */
+ if (sam == special_array_member::trail_0
+ || sam == special_array_member::trail_1
+ || flexible_array_type_p (TREE_TYPE (TREE_OPERAND
(v,0))))
+ is_flexible_array = true;
+
+ if (!is_flexible_array)
{
v = NULL_TREE;
