[Bug c/121217] [15/16 regression] internal compiler error: Segmentation fault comptypes_equiv_p since 15.1 with -std=c2x

[uecker at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121217

--- Comment #2 from uecker at gcc dot gnu.org ---

Tentative patch

diff --git a/gcc/c/c-typeck.cc b/gcc/c/c-typeck.cc
index b46eb43bb5a..27cfb61c88d 100644
--- a/gcc/c/c-typeck.cc
+++ b/gcc/c/c-typeck.cc
@@ -1970,6 +1970,9 @@ tagged_types_tu_compatible_p (const_tree t1, const_tree
t2,
                ft2 = DECL_BIT_FIELD_TYPE (s2);
              }

+           if (!ft1 || !ft2)
+             return false;
+
            if (TREE_CODE (ft1) == ERROR_MARK || TREE_CODE (ft2) == ERROR_MARK)
              return false;