py: Making closures now passes pointer to stack, not a tuple for vars.

Closed over variables are now passed on the stack, instead of creating a
tuple and passing that.  This way memory for the closed over variables
can be allocated within the closure object itself.  See issue #510 for
background.

1 files changed, 17 insertions, 17 deletions

diff --git a/py/objclosure.c b/py/objclosure.c
index de7554385..09371b034 100644
--- a/py/objclosure.c
+++ b/py/objclosure.c
@@ -11,28 +11,28 @@
 typedef struct _mp_obj_closure_t {
     mp_obj_base_t base;
     mp_obj_t fun;
-    mp_obj_tuple_t *closure_tuple;
+    machine_uint_t n_closed;
+    mp_obj_t closed[];
 } mp_obj_closure_t;
 
 mp_obj_t closure_call(mp_obj_t self_in, uint n_args, uint n_kw, const mp_obj_t *args) {
     mp_obj_closure_t *self = self_in;
-    mp_obj_tuple_t *t = self->closure_tuple;
 
     // need to concatenate closed-over-vars and args
 
-    int n_total = t->len + n_args + 2 * n_kw;
+    int n_total = self->n_closed + n_args + 2 * n_kw;
     if (n_total <= 5) {
         // use stack to allocate temporary args array
         mp_obj_t args2[5];
-        memcpy(args2, t->items, t->len * sizeof(mp_obj_t));
-        memcpy(args2 + t->len, args, (n_args + 2 * n_kw) * sizeof(mp_obj_t));
-        return mp_call_function_n_kw(self->fun, t->len + n_args, n_kw, args2);
+        memcpy(args2, self->closed, self->n_closed * sizeof(mp_obj_t));
+        memcpy(args2 + self->n_closed, args, (n_args + 2 * n_kw) * sizeof(mp_obj_t));
+        return mp_call_function_n_kw(self->fun, self->n_closed + n_args, n_kw, args2);
     } else {
         // use heap to allocate temporary args array
         mp_obj_t *args2 = m_new(mp_obj_t, n_total);
-        memcpy(args2, t->items, t->len * sizeof(mp_obj_t));
-        memcpy(args2 + t->len, args, (n_args + 2 * n_kw) * sizeof(mp_obj_t));
-        mp_obj_t res = mp_call_function_n_kw(self->fun, t->len + n_args, n_kw, args2);
+        memcpy(args2, self->closed, self->n_closed * sizeof(mp_obj_t));
+        memcpy(args2 + self->n_closed, args, (n_args + 2 * n_kw) * sizeof(mp_obj_t));
+        mp_obj_t res = mp_call_function_n_kw(self->fun, self->n_closed + n_args, n_kw, args2);
         m_del(mp_obj_t, args2, n_total);
         return res;
     }
@@ -41,13 +41,12 @@ mp_obj_t closure_call(mp_obj_t self_in, uint n_args, uint n_kw, const mp_obj_t *
 #if 0
 STATIC void closure_print(void (*print)(void *env, const char *fmt, ...), void *env, mp_obj_t o_in, mp_print_kind_t kind) {
     mp_obj_closure_t *o = o_in;
-    print(env, "<closure %p (closed: %p) ", o, o->closure_tuple);
-    mp_obj_tuple_t *t = o->closure_tuple;
-    for (int i = 0; i < t->len; i++) {
-        if (t->items[i] == MP_OBJ_NULL) {
+    print(env, "<closure %p, n_closed=%u ", o, o->n_closed);
+    for (int i = 0; i < o->n_closed; i++) {
+        if (o->closed[i] == MP_OBJ_NULL) {
             print(env, "(nil)");
         } else {
-            mp_obj_print_helper(print, env, t->items[i], PRINT_REPR);
+            mp_obj_print_helper(print, env, o->closed[i], PRINT_REPR);
         }
         print(env, " ");
     }
@@ -62,10 +61,11 @@ const mp_obj_type_t closure_type = {
     .call = closure_call,
 };
 
-mp_obj_t mp_obj_new_closure(mp_obj_t fun, mp_obj_t closure_tuple) {
-    mp_obj_closure_t *o = m_new_obj(mp_obj_closure_t);
+mp_obj_t mp_obj_new_closure(mp_obj_t fun, uint n_closed_over, const mp_obj_t *closed) {
+    mp_obj_closure_t *o = m_new_obj_var(mp_obj_closure_t, mp_obj_t, n_closed_over);
     o->base.type = &closure_type;
     o->fun = fun;
-    o->closure_tuple = closure_tuple;
+    o->n_closed = n_closed_over;
+    memcpy(o->closed, closed, n_closed_over * sizeof(mp_obj_t));
     return o;
 }