/* Check if we have a nullable alternate inside a nullable iterator */
static int rdp_check_nested_nullable(void * base)
{
int bad = 0;
rdp_data * temp =(rdp_data *) symbol_next_symbol_in_scope(base);
while (temp != NULL)
{
if (set_includes_element(& rdp_production_set, temp->kind)&& temp->kind != K_SEQUENCE)
{
rdp_list * inner = temp->list;
while (inner != NULL)
{
if (temp->lo == 0 && inner->production->contains_null)
{
text_message(TEXT_ERROR, "LL(1) violation - rule \'%s\'\n is nullable but contains the nullable subrule\n", temp->id);
text_printf(" %s ::= ", inner->production->id);
rdp_print_sub_item(inner->production, 1);
text_printf(".\n");
bad = 1;
temp->ll1_violation = 1;
inner->production->ll1_violation = 1;
}
inner = inner->next;
}
}
temp =(rdp_data *) symbol_next_symbol_in_scope(temp);
}
return bad;
}
static int rdp_check_disjoint(void * base)
{
int bad = 0;
set_ work = SET_NULL;
rdp_data * temp =(rdp_data *) symbol_next_symbol_in_scope(base);
while (temp != NULL)
{
if (set_includes_element(& rdp_production_set, temp->kind)&& temp->kind != K_SEQUENCE)
{
rdp_list * left = temp->list;
while (left != NULL)
{
rdp_list * right = left->next;
while (right != NULL)
{
/* First check for disjoint on epsilon */
if (left->production->contains_null && right->production->contains_null)
{
text_message(TEXT_ERROR, "LL(1) violation - rule \'%s\'\n", temp->id);
text_printf(" productions %s ::= ", left->production->id);
rdp_print_sub_item(left->production, 1);
text_printf(".\n and %s ::= ", right->production->id);
rdp_print_sub_item(right->production, 1);
text_printf(".\n are both nullable \n");
left->production->ll1_violation = 1;
right->production->ll1_violation = 1;
bad = 1;
}
set_assign_set(& work, & left->production->first);
set_intersect_set(& work, & right->production->first);
if (set_cardinality(& work)!= 0)
{
text_message(TEXT_ERROR, "LL(1) violation - rule \'%s\'\n", temp->id);
text_printf(" productions %s ::= ", left->production->id);
rdp_print_sub_item(left->production, 1);
text_printf(".\n and %s ::= ", right->production->id);
rdp_print_sub_item(right->production, 1);
text_printf(".\n share these start tokens: ");
set_print_set(& work, rdp_token_string, 78);
text_printf("\n");
left->production->ll1_violation = 1;
right->production->ll1_violation = 1;
bad = 1;
}
right = right->next;
}
left = left->next;
}
}
temp =(rdp_data *) symbol_next_symbol_in_scope(temp);
}
return bad;
}
static void scan_skip(set_ * stop) /* scan until a token in stop set appears */
{
while (!set_includes_element(stop, SCAN_CAST->token))
scan_(); /* Don't add tokens to tree when skipping! */
if (scan_show_skips)
text_message(TEXT_ERROR_ECHO, "Skipping to...\n");
}
int scan_test_set(const char * production, set_ * valid, set_ * stop)
{
if (!set_includes_element(valid, SCAN_CAST->token))
{
if (stop != NULL)
{
if (production != NULL)
text_message(TEXT_ERROR_ECHO, "In rule \'%s\', scanned ", production);
else
text_message(TEXT_ERROR_ECHO, "Scanned ");
set_print_element(SCAN_CAST->token, scan_token_names);
text_printf(" whilst expecting %s", set_cardinality(valid)== 1 ? "": "one of ");
set_print_set(valid, scan_token_names, 60);
text_printf("\n");
scan_skip(stop);
}
return 0;
}
else
return 1;
}
