add initial reference invalidation

+ Makes vec example actually memory safe, which is cool

+ Specify owner > sub relationships with ">" in closure parameter
  lists, uses the same group idea as closure calls

+ Relies on users implementing functions in a consistent manner,
  since you can kind of do whatever with pointers. Presumably
  there would be a stdlib of vec/map/set etc. which applications
  could then use and by proxy be memory safe. Although some more
  checks wouldn't hurt, I suppose?

+ Not sure I like having reference invalidation be 'just a move',
  seems to work alright but the semantics of it are a bit muddy.

1 files changed, 12 insertions, 0 deletions

diff --git a/src/ast.c b/src/ast.c
index d7d97e0..4573d3e 100644
--- a/src/ast.c
+++ b/src/ast.c
@@ -123,6 +123,8 @@ struct ast *gen_ast(enum ast_kind kind,
 	n->s = s;
 	n->v = v;
 	n->d = d;
+	n->or = NULL;
+	n->ol = NULL;
 	n->loc = loc;
 	return n;
 }
@@ -139,6 +141,7 @@ struct type *tgen_type(enum type_kind kind,
 	n->k = kind;
 	n->t0 = t0;
 	n->id = id;
+	n->or = NULL;
 	n->loc = loc;
 	return n;
 }
@@ -378,6 +381,7 @@ struct type *clone_type(struct type *type)
 	if (type->t0)
 		new->t0 = clone_type_list(type->t0);
 
+	new->or = type->or;
 	new->group = type->group;
 	new->loc = type->loc;
 	return new;
@@ -752,3 +756,11 @@ void opt_group(struct ast *a, struct ast *b)
 	a->or = b;
 	b->ol = a;
 }
+
+void own_type_group(struct type *owner, struct type *sub)
+{
+	/* sub does not get a reference to owner so if owner is moved, only the
+	 * sub is marked as used. sub is still allowed to be passed around
+	 * freely */
+	owner->or = sub;
+}