has_unique_object_representations returns false for classes whose base has only inherited members

[jakub-labenski]

Issue Summary

type_has_unique_object_representations (folding.c) treats a direct base class as empty when its own field_list is NULL, ignoring the data inherited from its bases. Such a base contributes 0 bytes to the computed layout, so the tail-padding check fails and the trait wrongly evaluates to false.

Observed Behavior

Reproducer:

//remark:type_has_unique_object_representations
//options:--g++ --gnu_version=150100;fp
struct A { char i; };
struct B : A {};
struct C : B {};
static_assert(__has_unique_object_representations(B));  // passes
static_assert(__has_unique_object_representations(C));  // fails, expected to pass

edg-docker-test and then edg-test-run-diff returns:

--- Expected Output (sandbox/test.sft.rt.tar.gz -- edg_x86_64)
+++ Observed Output (sandbox/test.sft.rt.tar.gz -- edg_x86_64)
# fe_only -DTEST_NUMBER=1 --g++ --gnu_version=150100 Test_name.c
@@ -0,0 +1,5 @@
+"Test_name.c", line 7: error: static assertion failed
+  static_assert(__has_unique_object_representations(C));  // fails, expected to pass
+  ^
+
+1 error detected in the compilation of "Test_name.c".

Expected Behavior

Code should compile correctly.

Additional Details

No response

I acknowledge that:

• I have checked open issues and existing discussions before filing this report.