--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/testsuite/c-c++-common/Wsizeof-pointer-memaccess4.c	Thu Feb 13 11:34:05 2020 +0900
@@ -0,0 +1,36 @@
+/* PR c/88065 - ICE in -Wsizeof-pointer-memaccess on an invalid strncpy
+   PR c/87297 - ICE on strncpy with an undeclared argument
+   { dg-do compile }
+   { dg-options "-Wall -Wsizeof-pointer-memaccess" } */
+
+typedef __SIZE_TYPE__ size_t;
+
+char* strncpy (char*, const char*, size_t);
+
+struct A { char a[4], b[6]; };
+
+void test_invalid_dst (struct A *p)
+{
+  strncpy (q->a, p->b, sizeof p->b);    /* { dg-error ".q. undeclared|not declared" } */
+}
+
+void test_invalid_src (struct A *p)
+{
+  strncpy (p->a, q->b, sizeof p->b);    /* { dg-error ".q. undeclared|not declared" } */
+}
+
+void test_invalid_bound (struct A *p)
+{
+  strncpy (p->a, p->b, sizeof q->b);    /* { dg-error ".q. undeclared|not declared" } */
+}
+
+/* Verify the C++ front end doesn't ICE (the verifies that the fix
+   for PR c/87297 uses error_operand_p to detect the invalid source
+   argument rather than just checking its equality to error_mark_node.  */
+struct B { char a[4]; };
+
+void test_cxx_invalid_dst (struct B *p, const char *s)
+{
+  struct T x;	                        /* { dg-error "storage size|incomplete type|unused" } */
+  __builtin_strncpy (x, s, sizeof p->a);
+}