py: Simplify stack get/set to become stack adjust in emitters.

Can do this now that the stack size calculation is improved.

py/compile.c

@@ -1595,7 +1595,7 @@ void compile_for_stmt_optimised_range(compiler_t *comp, mp_parse_node_t pn_var,
     EMIT_ARG(label_assign, top_label);
 
     // at this point we actually have 1 less element on the stack
-    EMIT_ARG(set_stack_size, EMIT(get_stack_size) - 1);
+    EMIT_ARG(adjust_stack_size, -1);
 
     // store next value to var
     c_assign(comp, pn_var, ASSIGN_STORE);
@@ -1728,7 +1728,7 @@ void compile_try_except(compiler_t *comp, mp_parse_node_t pn_body, int n_except,
     EMIT_ARG(jump, success_label); // jump over exception handler
 
     EMIT_ARG(label_assign, l1); // start of exception handler
-    EMIT_ARG(set_stack_size, EMIT(get_stack_size) + 6); // stack adjust for the 3 exception items, +3 for possible UNWIND_JUMP state
+    EMIT_ARG(adjust_stack_size, 6); // stack adjust for the 3 exception items, +3 for possible UNWIND_JUMP state
 
     uint l2 = comp_next_label(comp);
 
@@ -1795,12 +1795,12 @@ void compile_try_except(compiler_t *comp, mp_parse_node_t pn_body, int n_except,
         }
         EMIT_ARG(jump, l2);
         EMIT_ARG(label_assign, end_finally_label);
-        EMIT_ARG(set_stack_size, EMIT(get_stack_size) + 3); // stack adjust for the 3 exception items
+        EMIT_ARG(adjust_stack_size, 3); // stack adjust for the 3 exception items
     }
 
     compile_decrease_except_level(comp);
     EMIT(end_finally);
-    EMIT_ARG(set_stack_size, EMIT(get_stack_size) - 5); // stack adjust
+    EMIT_ARG(adjust_stack_size, -5); // stack adjust
 
     EMIT_ARG(label_assign, success_label);
     compile_node(comp, pn_else); // else block, can be null
@@ -1815,9 +1815,9 @@ void compile_try_finally(compiler_t *comp, mp_parse_node_t pn_body, int n_except
 
     if (n_except == 0) {
         assert(MP_PARSE_NODE_IS_NULL(pn_else));
-        EMIT_ARG(set_stack_size, EMIT(get_stack_size) + 3); // stack adjust for possible UNWIND_JUMP state
+        EMIT_ARG(adjust_stack_size, 3); // stack adjust for possible UNWIND_JUMP state
         compile_node(comp, pn_body);
-        EMIT_ARG(set_stack_size, EMIT(get_stack_size) - 3);
+        EMIT_ARG(adjust_stack_size, -3);
     } else {
         compile_try_except(comp, pn_body, n_except, pn_except, pn_else);
     }
@@ -2027,7 +2027,7 @@ void compile_test_if_expr(compiler_t *comp, mp_parse_node_struct_t *pns) {
     compile_node(comp, pns->nodes[0]); // success value
     EMIT_ARG(jump, l_end);
     EMIT_ARG(label_assign, l_fail);
-    EMIT_ARG(set_stack_size, EMIT(get_stack_size) - 1); // adjust stack size
+    EMIT_ARG(adjust_stack_size, -1); // adjust stack size
     compile_node(comp, pns_test_if_else->nodes[1]); // failure value
     EMIT_ARG(label_assign, l_end);
 }
@@ -2134,7 +2134,7 @@ void compile_comparison(compiler_t *comp, mp_parse_node_struct_t *pns) {
         uint l_end = comp_next_label(comp);
         EMIT_ARG(jump, l_end);
         EMIT_ARG(label_assign, l_fail);
-        EMIT_ARG(set_stack_size, EMIT(get_stack_size) + 1);
+        EMIT_ARG(adjust_stack_size, 1);
         EMIT(rot_two);
         EMIT(pop_top);
         EMIT_ARG(label_assign, l_end);

py/emit.h

@@ -24,8 +24,7 @@ typedef struct _emit_method_table_t {
     void (*start_pass)(emit_t *emit, pass_kind_t pass, scope_t *scope);
     void (*end_pass)(emit_t *emit);
     bool (*last_emit_was_return_value)(emit_t *emit);
-    int (*get_stack_size)(emit_t *emit);
-    void (*set_stack_size)(emit_t *emit, int size);
+    void (*adjust_stack_size)(emit_t *emit, int delta);
     void (*set_line_number)(emit_t *emit, int line);
 
     void (*load_id)(emit_t *emit, qstr qstr);

py/emitbc.c

@@ -292,12 +292,8 @@ STATIC bool emit_bc_last_emit_was_return_value(emit_t *emit) {
     return emit->last_emit_was_return_value;
 }
 
-STATIC int emit_bc_get_stack_size(emit_t *emit) {
-    return emit->stack_size;
-}
-
-STATIC void emit_bc_set_stack_size(emit_t *emit, int size) {
-    emit->stack_size = size;
+STATIC void emit_bc_adjust_stack_size(emit_t *emit, int delta) {
+    emit->stack_size += delta;
 }
 
 STATIC void emit_bc_set_source_line(emit_t *emit, int source_line) {
@@ -836,8 +832,7 @@ const emit_method_table_t emit_bc_method_table = {
     emit_bc_start_pass,
     emit_bc_end_pass,
     emit_bc_last_emit_was_return_value,
-    emit_bc_get_stack_size,
-    emit_bc_set_stack_size,
+    emit_bc_adjust_stack_size,
     emit_bc_set_source_line,
 
     emit_bc_load_id,

py/emitcpy.c

@@ -60,12 +60,8 @@ STATIC bool emit_cpy_last_emit_was_return_value(emit_t *emit) {
     return emit->last_emit_was_return_value;
 }
 
-STATIC int emit_cpy_get_stack_size(emit_t *emit) {
-    return emit->stack_size;
-}
-
-STATIC void emit_cpy_set_stack_size(emit_t *emit, int size) {
-    emit->stack_size = size;
+STATIC void emit_cpy_adjust_stack_size(emit_t *emit, int delta) {
+    emit->stack_size += delta;
 }
 
 STATIC void emit_cpy_set_source_line(emit_t *emit, int source_line) {
@@ -793,8 +789,7 @@ const emit_method_table_t emit_cpython_method_table = {
     emit_cpy_start_pass,
     emit_cpy_end_pass,
     emit_cpy_last_emit_was_return_value,
-    emit_cpy_get_stack_size,
-    emit_cpy_set_stack_size,
+    emit_cpy_adjust_stack_size,
     emit_cpy_set_source_line,
 
     emit_cpy_load_id,

py/emitnative.c

@@ -295,12 +295,8 @@ STATIC bool emit_native_last_emit_was_return_value(emit_t *emit) {
     return emit->last_emit_was_return_value;
 }
 
-STATIC int emit_native_get_stack_size(emit_t *emit) {
-    return emit->stack_size;
-}
-
-STATIC void emit_native_set_stack_size(emit_t *emit, int size) {
-    emit->stack_size = size;
+STATIC void emit_native_adjust_stack_size(emit_t *emit, int delta) {
+    emit->stack_size += delta;
 }
 
 STATIC void emit_native_set_source_line(emit_t *emit, int source_line) {
@@ -1304,8 +1300,7 @@ const emit_method_table_t EXPORT_FUN(method_table) = {
     emit_native_start_pass,
     emit_native_end_pass,
     emit_native_last_emit_was_return_value,
-    emit_native_get_stack_size,
-    emit_native_set_stack_size,
+    emit_native_adjust_stack_size,
     emit_native_set_source_line,
 
     emit_native_load_id,

py/emitpass1.c

@@ -39,10 +39,6 @@ STATIC bool emit_pass1_last_emit_was_return_value(emit_t *emit) {
     return false;
 }
 
-STATIC int emit_pass1_get_stack_size(emit_t *emit) {
-    return 0;
-}
-
 STATIC void emit_pass1_load_id(emit_t *emit, qstr qstr) {
     // name adding/lookup
     bool added;
@@ -108,7 +104,6 @@ const emit_method_table_t emit_pass1_method_table = {
     emit_pass1_start_pass,
     emit_pass1_end_pass,
     emit_pass1_last_emit_was_return_value,
-    emit_pass1_get_stack_size,
     (void*)emit_pass1_dummy,
     (void*)emit_pass1_dummy,