bpf: avoid potential NULL pointer dereference

If the result from SSA_NAME_DEF_STMT is NULL, we could try to
dereference it anyway and ICE. Avoid this.

gcc/ChangeLog:

	* config/bpf/bpf.c (handle_attr_preserve): Avoid calling
	is_gimple_assign with a NULL pointer.

diff --git a/gcc/config/bpf/bpf.c b/gcc/config/bpf/bpf.c
index 9d2c0bb..c054c1e 100644 (file)
--- a/gcc/config/bpf/bpf.c
+++ b/gcc/config/bpf/bpf.c
@@ -1482,7 +1482,7 @@ handle_attr_preserve (function *fn)
                      && TREE_CODE (TREE_OPERAND (expr, 0)) == SSA_NAME)
                    {
                      gimple *def_stmt = SSA_NAME_DEF_STMT (TREE_OPERAND (expr, 0));
-                     if (is_gimple_assign (def_stmt))
+                     if (def_stmt && is_gimple_assign (def_stmt))
                        expr = gimple_assign_rhs1 (def_stmt);
                    }