From bb58afb57221eb0316d6ee14e19c5f4c4a822ba1 Mon Sep 17 00:00:00 2001
From: Bad Diode <bd@badd10de.dev>
Date: Sat, 16 Oct 2021 21:22:08 +0200
Subject: Add a working GC with mark-and-sweep

---
 src/bootstrap/primitives.c | 47 +++++++++++++++++++++++++++++++++++-----------
 1 file changed, 36 insertions(+), 11 deletions(-)

(limited to 'src/bootstrap/primitives.c')

diff --git a/src/bootstrap/primitives.c b/src/bootstrap/primitives.c
index 35208b0..abb87e7 100644
--- a/src/bootstrap/primitives.c
+++ b/src/bootstrap/primitives.c
@@ -2,7 +2,6 @@
 
 Object *
 eval(Environment* env, Object *root) {
-    return obj_nil; // DEBUG: gc
     switch (root->type) {
         case OBJ_TYPE_ERR:
         case OBJ_TYPE_PROCEDURE:
@@ -95,7 +94,8 @@ eval_lambda:
                     };
                     root = root->cdr;
                 }
-                return eval(env, root->car);
+                root = eval(env, root->car);
+                return root;
             }
         } break;
     }
@@ -630,9 +630,20 @@ proc_cons(Environment *env, Object *obj) {
         });
         return obj_err;
     }
-    Object *a = eval(env, obj->car);
-    Object *b = eval(env, obj->cdr->car);
-    return make_pair(a, b);
+    Object *head = make_pair(obj_nil, obj_nil);
+    push_root(head);
+    head->car = eval(env, obj->car);
+    if (head->car == obj_err) {
+        pop_root();
+        return obj_err;
+    }
+    head->cdr = eval(env, obj->cdr->car);
+    if (head->cdr == obj_err) {
+        pop_root();
+        return obj_err;
+    }
+    pop_root();
+    return head;
 }
 
 Object *
@@ -640,14 +651,28 @@ proc_list(Environment *env, Object *obj) {
     if (obj == obj_nil) {
         return obj_nil;
     }
-    Object *head = make_pair(eval(env, obj->car), obj_nil);
+
+    Object *head = make_pair(obj_nil, obj_nil);
+    push_root(head);
+    Object *tmp = eval(env, obj->car);
+    if (tmp == obj_err) {
+        pop_root();
+        return obj_err;
+    }
+    head->car = tmp;
     Object *curr = head;
     obj = obj->cdr;
     while (obj != obj_nil) {
-        curr->cdr = make_pair(eval(env, obj->car), obj_nil);
+        tmp = eval(env, obj->car);
+        if (tmp == obj_err) {
+            pop_root();
+            return obj_err;
+        }
+        curr->cdr = make_pair(tmp, obj_nil);
         curr = curr->cdr;
         obj = obj->cdr;
     }
+    pop_root();
     return head;
 }
 
@@ -753,8 +778,8 @@ proc_lambda(Environment *env, Object *obj) {
     }
     Object *body = obj->cdr;
     Object *fun = alloc_object(OBJ_TYPE_LAMBDA);
-    fun->params = obj_duplicate(params);
-    fun->body = obj_duplicate(body);
+    fun->params = params;
+    fun->body = body;
     fun->env = env;
     return fun;
 }
@@ -788,8 +813,8 @@ proc_fun(Environment *env, Object *obj) {
     }
     Object *body = obj->cdr->cdr;
     Object *fun = alloc_object(OBJ_TYPE_LAMBDA);
-    fun->params = obj_duplicate(params);
-    fun->body = obj_duplicate(body);
+    fun->params = params;
+    fun->body = body;
     fun->env = env;
     env_add_or_update_current(env, name, fun);
     return obj_nil;
-- 
cgit v1.2.1