lang: fix a bunch of memory leaks

lang/ast/ctx.c

@@ -39,8 +39,31 @@ enum ivy_status ivy_parser_create(struct ivy_parser **parser)
 	return IVY_OK;
 }
 
-void ivy_parser_destroy(struct ivy_parser *parser)
+void ivy_parser_destroy(struct ivy_parser *parser, struct ivy_ast_node **result)
 {
+	struct ivy_ast_node *root = NULL;
+
+	b_queue_iterator it;
+	b_queue_iterator_begin(&parser->p_state, &it);
+	while (b_queue_iterator_is_valid(&it)) {
+		struct parser_state *state
+			= b_unbox(struct parser_state, it.entry, s_entry);
+		b_queue_iterator_erase(&it);
+
+		if (root) {
+			ivy_ast_node_destroy(root);
+		}
+
+		root = state->s_node;
+		free(state);
+	}
+
+	if (result) {
+		*result = root;
+	} else if (root) {
+		ivy_ast_node_destroy(root);
+	}
+
 	free(parser);
 }
 

lang/ast/node.c

@@ -252,6 +252,47 @@ void ivy_ast_node_to_string(struct ivy_ast_node *node, struct b_string *out)
 
 void ivy_ast_node_destroy(struct ivy_ast_node *node)
 {
+	struct ivy_ast_node_iterator it = {};
+	b_queue_push_back(&it.it_queue, &node->n_it.it_entry);
+	node->n_it.it_depth = 0;
+
+	b_queue_iterator q_it;
+	b_queue_iterator_begin(&it.it_queue, &q_it);
+
+	while (b_queue_iterator_is_valid(&q_it)) {
+		struct ivy_ast_node_iterator_entry *it_entry = b_unbox(
+			struct ivy_ast_node_iterator_entry, q_it.entry, it_entry);
+		node = b_unbox(struct ivy_ast_node, it_entry, n_it);
+
+		if (!node) {
+			/* this should never happen. */
+			return;
+		}
+
+		const struct ast_node_type *type = get_ast_node_type(node->n_type);
+		if (type->n_collect_children) {
+			it.it_insert_after = q_it.entry;
+			type->n_collect_children(node, &it);
+		}
+
+		b_queue_iterator_next(&q_it);
+	}
+
+	while (!b_queue_empty(&it.it_queue)) {
+		b_queue_entry *entry = b_queue_pop_back(&it.it_queue);
+		if (!entry) {
+			break;
+		}
+
+		node = b_unbox(struct ivy_ast_node, entry, n_it);
+
+		const struct ast_node_type *type = get_ast_node_type(node->n_type);
+		if (type && type->n_destroy) {
+			type->n_destroy(node);
+		}
+
+		free(node);
+	}
 }
 
 #define ENUM_STR(x)                                                            \

lang/ast/node.h

@@ -50,6 +50,7 @@ struct ast_node_type {
 	void (*n_init_state)(struct ivy_parser *, struct parser_state *, uintptr_t);
 	void (*n_collect_children)(
 		struct ivy_ast_node *, struct ivy_ast_node_iterator *);
+	void (*n_destroy)(struct ivy_ast_node *);
 
 	size_t n_state_size;
 	size_t n_node_size;

lang/include/ivy/lang/ast.h

@@ -329,7 +329,8 @@ typedef enum ivy_status (*ivy_ast_node_iteration_callback)(
 	struct ivy_ast_node_iterator *, void *);
 
 IVY_API enum ivy_status ivy_parser_create(struct ivy_parser **parser);
-IVY_API void ivy_parser_destroy(struct ivy_parser *parser);
+IVY_API void ivy_parser_destroy(
+	struct ivy_parser *parser, struct ivy_ast_node **result);
 
 IVY_API enum ivy_status ivy_parser_get_status(struct ivy_parser *parser);
 IVY_API bool ivy_parser_is_node_complete(struct ivy_parser *parser);