py: Use nlr jump callbacks to optimise compile/execute functions.

The changed functions now use less stack, and don't have any issues with
local variables needing to be declared volatile.

Testing on a PYBv1.0, imports (of .py, .mpy and frozen code) now use 64
less bytes of C stack per import depth.

Signed-off-by: Damien George <damien@micropython.org>

1 files changed, 9 insertions, 0 deletions

diff --git a/py/runtime.h b/py/runtime.h
index 9b99e594b..78194973d 100644
--- a/py/runtime.h
+++ b/py/runtime.h
@@ -66,6 +66,13 @@ typedef struct _mp_sched_node_t {
     struct _mp_sched_node_t *next;
 } mp_sched_node_t;
 
+// For use with mp_globals_locals_set_from_nlr_jump_callback.
+typedef struct _nlr_jump_callback_node_globals_locals_t {
+    nlr_jump_callback_node_t callback;
+    mp_obj_dict_t *globals;
+    mp_obj_dict_t *locals;
+} nlr_jump_callback_node_globals_locals_t;
+
 // Tables mapping operator enums to qstrs, defined in objtype.c
 extern const byte mp_unary_op_method_name[];
 extern const byte mp_binary_op_method_name[];
@@ -113,6 +120,8 @@ static inline void mp_globals_set(mp_obj_dict_t *d) {
     MP_STATE_THREAD(dict_globals) = d;
 }
 
+void mp_globals_locals_set_from_nlr_jump_callback(void *ctx_in);
+
 mp_obj_t mp_load_name(qstr qst);
 mp_obj_t mp_load_global(qstr qst);
 mp_obj_t mp_load_build_class(void);