Fix crash with unconstrained type in has_unique_driver. Fixes xxx

src/driver.c

@@ -333,6 +333,9 @@ bool has_unique_driver(driver_set_t *ds, tree_t what)
       return true;
 
    type_t type = tree_type(what);
+   if (type_is_unconstrained(type))
+      return false;
+
    int64_t length = 0, left = 0, right = 0;
    range_kind_t rkind = RANGE_ERROR;
    if (type_is_array(type) && dimension_of(type) == 1) {

test/driver/issue953.vhd

@@ -0,0 +1,17 @@
+entity issue953 is
+end entity;
+
+architecture test of issue953 is
+    signal s : bit_vector(1 to 2);
+begin
+
+    -- Crash with unconstrained port in has_unique_driver
+    b: block is
+        port ( p : out bit_vector );
+        port map ( s );
+    begin
+        p(1) <= '1';
+        p(2) <= '0';
+    end block;
+
+end architecture;

test/test_driver.c

@@ -243,6 +243,26 @@ START_TEST(test_issue930)
 }
 END_TEST
 
+START_TEST(test_issue953)
+{
+   input_from_file(TESTDIR "/driver/issue953.vhd");
+
+   tree_t a = parse_check_and_simplify(T_ENTITY, T_ARCH);
+
+   tree_t b = tree_stmt(a, 0);
+   fail_unless(tree_kind(b) == T_BLOCK);
+
+   driver_set_t *ds = find_drivers(b);
+
+   tree_t p = tree_port(b, 0);
+   ck_assert(!has_unique_driver(ds, p));
+
+   free_drivers(ds);
+
+   fail_if_errors();
+}
+END_TEST
+
 Suite *get_driver_tests(void)
 {
    Suite *s = suite_create("driver");
@@ -254,6 +274,7 @@ Suite *get_driver_tests(void)
    tcase_add_test(tc, test_unique2);
    tcase_add_test(tc, test_unique3);
    tcase_add_test(tc, test_issue930);
+   tcase_add_test(tc, test_issue953);
    suite_add_tcase(s, tc);
 
    return s;