wip

assets/parser.c.erb

@@ -666,6 +666,28 @@ void state_values_stack_init(state_values_stack_t * stack)
     stack->entries = (state_value_t *)malloc(initial_capacity * sizeof(state_value_t));
 }
 
+/**
+ * Index a state_values stack.
+ *
+ * @param stack
+ *   state_values stack structure.
+ * @param index
+ *   Index to the stack.
+ *
+ * @return Pointer to the state value structure at the given index.
+ */
+state_value_t * state_values_stack_index(state_values_stack_t * stack, int index)
+{
+    if (index >= 0)
+    {
+        return &stack->entries[index];
+    }
+    else
+    {
+        return &stack->entries[stack->length - (size_t)(unsigned int)(-index)];
+    }
+}
+
 /**
  * Push a new state_value to the state_values stack.
  *
@@ -689,6 +711,30 @@ void state_values_stack_push(state_values_stack_t * stack)
     stack->length = current_length + 1u;
 }
 
+/**
+ * Pop entries from a state_values stack.
+ *
+ * @param stack
+ *   state_values stack structure.
+ * @param n
+ *   Number of states to pop.
+ */
+void state_values_stack_pop(state_values_stack_t * stack, size_t n)
+{
+    stack->length -= n;
+}
+
+/**
+ * Free memory for a state_values stack structure.
+ *
+ * @param stack
+ *   state_values stack structure.
+ */
+void state_values_stack_free(state_values_stack_t * stack)
+{
+     free(stack->entries);
+}
+
 /**
  * Execute user code associated with a parser rule.
  *
@@ -696,7 +742,7 @@ void state_values_stack_push(state_values_stack_t * stack)
  *
  * @return Parse value.
  */
-static <%= @grammar.prefix %>value_t parser_user_code(uint32_t rule, state_value_t[] statevalues, uint32_t n_states)
+static <%= @grammar.prefix %>value_t parser_user_code(uint32_t rule, state_value_stack_t * statevalues, uint32_t n_states)
 {
     <%= @grammar.prefix %>value_t _pvalue;
 
@@ -785,9 +831,12 @@ size_t <%= @grammar.prefix %>parse(<%= @grammar.prefix %>context_t * context)
 {
     <%= @grammar.prefix %>token_info_t token_info;
     <%= @grammar.prefix %>token_t token = INVALID_TOKEN_ID;
-    state_value_t[] statevalues = new state_value_t[](1);
+    state_values_stack_t statevalues;
     size_t reduced_rule_set = INVALID_ID;
     <%= @grammar.prefix %>value_t reduced_parser_value;
+    state_values_stack_init(&statevalues);
+    state_values_stack_push(&statevalues);
+    size_t result;
     for (;;)
     {
         if (token == INVALID_TOKEN_ID)
@@ -795,39 +844,42 @@ size_t <%= @grammar.prefix %>parse(<%= @grammar.prefix %>context_t * context)
             size_t lexer_result = <%= @grammar.prefix %>lex(context, &token_info);
             if (lexer_result != P_SUCCESS)
             {
-                return lexer_result;
+                result = lexer_result;
+                break;
             }
             token = token_info.token;
         }
         size_t shift_state = INVALID_ID;
         if (reduced_rule_set != INVALID_ID)
         {
-            shift_state = check_shift(statevalues[$-1].state_id, reduced_rule_set);
+            shift_state = check_shift(state_value_stack_index(&statevalues, -1)->state_id, reduced_rule_set);
         }
         if (shift_state == INVALID_ID)
         {
-            shift_state = check_shift(statevalues[$-1].state_id, token);
+            shift_state = check_shift(state_value_stack_index(&statevalues, -1)->state_id, token);
             if ((shift_state != INVALID_ID) && (token == TOKEN___EOF))
             {
                 /* Successful parse. */
-                context.parse_result = statevalues[$-1].pvalue;
+                context.parse_result = state_value_stack_index(&statevalues, -1)->pvalue;
-                return P_SUCCESS;
+                result = P_SUCCESS;
+                break;
             }
         }
         if (shift_state != INVALID_ID)
         {
             /* We have something to shift. */
-            statevalues ~= state_value_t(shift_state);
+            state_value_stack_push(&statevalues);
+            state_value_stack_index(&statevalues, -1)->state_id = shift_state;
             if (reduced_rule_set == INVALID_ID)
             {
                 /* We shifted a token, mark it consumed. */
                 token = INVALID_TOKEN_ID;
-                statevalues[$-1].pvalue = token_info.pvalue;
+                state_value_stack_index(&statevalues, -1)->pvalue = token_info.pvalue;
             }
             else
             {
                 /* We shifted a RuleSet. */
-                statevalues[$-1].pvalue = reduced_parser_value;
+                state_value_stack_index(&statevalues, -1)->pvalue = reduced_parser_value;
                 <%= @grammar.prefix %>value_t new_parse_result;
                 reduced_parser_value = new_parse_result;
                 reduced_rule_set = INVALID_ID;
@@ -835,13 +887,13 @@ size_t <%= @grammar.prefix %>parse(<%= @grammar.prefix %>context_t * context)
             continue;
         }
 
-        size_t reduce_index = check_reduce(statevalues[$-1].state_id, token);
+        size_t reduce_index = check_reduce(state_value_stack_index(&statevalues, -1)->state_id, token);
         if (reduce_index != INVALID_ID)
         {
             /* We have something to reduce. */
-            reduced_parser_value = parser_user_code(parser_reduce_table[reduce_index].rule, statevalues, parser_reduce_table[reduce_index].n_states);
+            reduced_parser_value = parser_user_code(parser_reduce_table[reduce_index].rule, &statevalues, parser_reduce_table[reduce_index].n_states);
             reduced_rule_set = parser_reduce_table[reduce_index].rule_set;
-            statevalues.length -= parser_reduce_table[reduce_index].n_states;
+            state_value_stack_pop(&statevalues, parser_reduce_table[reduce_index].n_states);
             continue;
         }
 
@@ -852,8 +904,10 @@ size_t <%= @grammar.prefix %>parse(<%= @grammar.prefix %>context_t * context)
          * it will point to the correct position of the unexpected token. */
         context.text_position = token_info.position;
         context.token = token;
-        return P_UNEXPECTED_TOKEN;
+        result = P_UNEXPECTED_TOKEN;
+        break;
     }
+    state_values_stack_free(&statevalues);
 }
 
 /**