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, 12 insertions, 8 deletions

diff --git a/py/vm.c b/py/vm.c
index c8e4ba9f48..78a96a48cc 100644
--- a/py/vm.c
+++ b/py/vm.c
@@ -759,19 +759,23 @@ unwind_jump:
                     SET_TOP(mp_make_function_from_raw_code((mp_raw_code_t*)unum, TOP(), obj1));
                     DISPATCH();
 
-                ENTRY(MP_BC_MAKE_CLOSURE):
+                ENTRY(MP_BC_MAKE_CLOSURE): {
                     DECODE_PTR;
-                    // Stack layout: closure_tuple <- TOS
-                    SET_TOP(mp_make_closure_from_raw_code((mp_raw_code_t*)unum, TOP(), MP_OBJ_NULL, MP_OBJ_NULL));
+                    machine_uint_t n_closed_over = *ip++;
+                    // Stack layout: closed_overs <- TOS
+                    sp -= n_closed_over - 1;
+                    SET_TOP(mp_make_closure_from_raw_code((mp_raw_code_t*)unum, n_closed_over, sp));
                     DISPATCH();
+                }
 
-                ENTRY(MP_BC_MAKE_CLOSURE_DEFARGS):
+                ENTRY(MP_BC_MAKE_CLOSURE_DEFARGS): {
                     DECODE_PTR;
-                    // Stack layout: def_tuple def_dict closure_tuple <- TOS
-                    obj1 = POP();
-                    obj2 = POP();
-                    SET_TOP(mp_make_closure_from_raw_code((mp_raw_code_t*)unum, obj1, TOP(), obj2));
+                    machine_uint_t n_closed_over = *ip++;
+                    // Stack layout: def_tuple def_dict closed_overs <- TOS
+                    sp -= 2 + n_closed_over - 1;
+                    SET_TOP(mp_make_closure_from_raw_code((mp_raw_code_t*)unum, 0x100 | n_closed_over, sp));
                     DISPATCH();
+                }
 
                 ENTRY(MP_BC_CALL_FUNCTION):
                     DECODE_UINT;